Flutter Interview Questions & Answers | Flutter Developer Interview Questions | Edureka

[Music] foreign [Music] there is a high demand for mobile apps due to increase use of smartphones and mobile devices in our daily lives mobile apps have become an essential tool for businesses and individuals to engage with their customers communicate and access information on the go so resulting in that there is a demand for mobile developers too so here in this session we will understand what kind of questions will be asked in the flutter interview so without wasting much of time let us go and explore the agenda so first in our list is why flutter is in demand after which we will go and start with a beginner level flutter interview questions and after that we will see an intermediate level flutter interview questions so once we have done with the intermediate level then we will move on to advanced level flutter interview questions then we have scenario based flutter interview questions also and finally we will look into the tips how to crack and flutter interview but before we go ahead just make sure you subscribe to our edureka's YouTube channel and hit the Bell icon to stay updated with all the latest edureka videos and also if you are interested in flutter certification courses then you can check out the link that is given in the description box now moving ahead in this session as said we have a lot of mobile applications starting with entertainment apps to informational apps and we have an equal population who uses Android and iOS to create apps in multiple platforms might take a lot of time and effort here comes flutter into the picture flutter allows developers to create cross-platform applications with a single code base this means that the developers can write the code once and deploy it on both IOS and Android platforms saving time and efforts and this is the reason why flutter and flutter developers are in demand now if you take a look at the stats that compare flato and other app development Frameworks namely react native and ionic as you can see here the flutter has the major part in this graph and you need to understand that it is never late to learn flutter so with that let us go ahead and see beginner's flutter interview questions starting with we have the first question that is what is flutter flutter is a tool that developers used to make mobile apps that can work both on Android and iOS devices without having to write a separate code base for each platforms so this can save time and effort for developers and all of them to create apps that look and feel great on both platforms so as I said in the previous slide so it will save time and effort by creating a same code base for both Android and iOS so this you can tell as a major point for the flutter and also flutter uses a programming language called Art so which is very easy to learn and use for those who are familiar with the other languages also so flutter also offers a rich set of pre-built widgets and tools making it easier for the developers to create a beautiful and functional apps so let us see a sample answer flutter is a free and open source UI toolkit for building high quality native compiled applications for mobile web and desktop from a single code base so this is a sample answer that you can answer in your interview so moving ahead let us see our next question how is flutter different from other mobile amps development Frameworks Plateau is different from other mobile app development Frameworks in that it uses a single code base for building applications for multiple platforms as I said in the previous question it includes IOS and Android so flutter also uses a reactive programming model and a unique widget paste architecture that allows a faster rendering and customizable UI elements so we also have a lot of features that flutter provides where one of the most important feature is our fast development hence platter offers a Reload feature that allows developers to see a change in their code immediately without starting the application which means it processes like a speed of wind which speeds up the development process and the next feature that flutter offers is its expressive and flexible UI flutter uses a widget-based architecture right so that allows the building custom UI elements easily and quickly it also offers a large library of pre-built widgets that can be customized to create Unique Designs then we have another feature called native performances Plato uses a dart programming language which is compiled into a native machine code this makes the app build with flutter highly performant with smooth animations and quick reload time then also we have another feature that is our cross-platform development with flutter developers can build applications from multiple platforms like Android iOS web and desktop from a single code base and at last we have an open source feature flutter is an open source framework with a vast community that provides support documentation and a wide range of plugins and packages to choose from so while answering the interviewer you can tell these kind of features for differentiating the flutter from other Frameworks moving ahead with the third question what programming language is used in flutter as I said before flutter uses the dart programming language Dart is an object oriented class-based programming language that was developed by Google flatter uses dot to build the user interfaces components and business Logics of the mobile apps Dart is our modern language with features such as static typing async and a weight and ahead of time compilations which makes it a good fit for building high performance mobile apps with the flutter so let us move on to the fourth question what is widget in flutter basically widgets can be classified into two types that is the stateless and stateful widget stateless widget are immutable and cannot change once they are created whereas stateful widgets are mutable and can change their appearances based on the change in their internal State as I said before flutter provides a rich set of a pre-built widgets right such as the text image button list View and many more you can also create your own custom widgets by combining the existing widget or by creating new ones from the scratch widgets in flutter are designed to be composable which means that you can Nest widgets inside the other widgets to create complex user interfaces so this makes it easy to build complex responsive and beautiful user interfaces in flutter so I'll give you a sample answer for this question in flutter a widget is a basic building block for building user interface widgets are also used to create visual components such as buttons text fields and images and also can be composed together to create complex UI elements so you can answer this way to the interviewer also now we have the next question based on the widgets what is the difference between the stateful and stateless widget in flood as I said in the question number four that is what is which is in flatter we have stateless and stateful widget the main difference between the stateful and stateless widget in flutter is that the stateful widget can change their internal State while stateless widgets cannot change stateless widgets are immutable meaning that they cannot be changed once they are created they are designed to represent a part of user interfaces that does not depend on any changing data or user interactions for example our text widget that displays a static text which could be a stateless widget right for example you will have a app name for example let's take Instagram so we will be having just the Instagram name over there so if you touch on the Instagram you will don't see any changes over there right so it is just a static widget over there meaning the stateless widget so that can be an example for your stateless widget on the other hand the stateful widgets are designed to represent a part of the user interfaces so that can change dynamically based on the user interactions or the other changing data stateful widgets have the mutable state which means that they can change their appearances or the behavior over time for example there is a check box widget that can represent a Boolean value Boolean value is nothing but the true or false for example if you click on that you will have only the two options the zero or one it's like that okay so this Boolean value would be a stateful widget has its appearances and the values can change based on the user interactions to manage the state of the stateful widget the flutter provides a stateful widget and the state classes the state for widget classes represents the widget itself while the state class represents the mutable State associated with the widget the state object is created when the stateful widget is inserted into the widget tree and it persists until the widget is removed from the tree so if I want to give you a sample answer for this question it would be like in flat term stateless widgets are immutable and their properties cannot be changed while stateful widgets have mutable state that can change over time stateful widgets are used when the need to manage the state that changes dynamically such as the user input or the network request so this is a kind of a sample answer and also you can make your own sentence based on the understanding that you have on widgets so now let us move on to the next question what is the pub spec dot yaml file in flutter okay the pubspect.yaml file is configuration file that is used in flutter to define the metadata dependencies and assets for the flutter project so this file is an important file that keeps all the information about your flutter project as you can see it is written in yaml it means dyaml aren't markup language so it is written in this yaml format and it also contains the essential informations about the project such as the name of the project version author description and other configuration settings also so in this perspect.yamf file you can Define the dependencies required for your flutter project so dependencies are the third party packages that your project requires to function correctly so these packages are hosted on the dart package manager called The Pub you can specify the packaged name and the version range required by your project in the dependency section of the pubspec dot yaml file so how do you answer this in a simple form so this pubspect.yaml file in flutter is used to specify the dependencies and the configuration for a flutter project it contains the information such as the project name version and packages that the project depends on so you can also answer like this and also you can make up your own answer now let us move ahead and see our seventh question that is the difference between a hot restart and a hot reload in flutter so you need to understand we have hot reload and hot restart feature in flutter project as our hot restart completely restarts the app and rebuilds its state from scratch while a hot reload injects the updated code into the running app without starting the app or losing its current state hot reload is a faster way to make interactive changes to the apps UI during the development so if you look at the table here you will have a clear understanding of the difference between the hot reload and hot restart so once you look at the definition over here here for the hot reload it reloads the code changes and it updates the UI so if you look at the hot restart it restarts the entire app and reloads the code and the UI where it completely restarts and reloads the code from the scratch so it will take a lot of time to give you some results when you want to see the changes immediately so if you look at the execution time over here as I said previously so hot reload is faster than the restart whereas the hot reload restarts the entire app so it might take a lot of time so it is slower than the reload feature then let's look at the state preservations so whereas the hot reload preserves the App State whereas the hot restart where it resets the App State then we have the performance impact where the minimal impact on the app performance is shown in the hot reload so where if you look at the Hard reload feature there is a high impact on the app performances the use cases for hot reload is ideal for the UI changes and quick code iterations whereas the hot restart is used when the code changes requires a full app restart whereas if you want to restart a entire code and you want to see the changes so that you can use the hot restart then if you look at the limitations in hot reload it cannot apply all code changes without restarting so it reloads only the changes where you have made it will be showing you the output based on the changes that you have made there whereas if you take a look at the restart it requires more time to complete than the reload because it restarts the entire app right so it takes a lot of time to restart so there is a lot of limitations and the advantages at the same time for the both features so we don't have any particular answer for which is better or not so both has a limitations and the advantages so with that let us move on and see our eighth question what is the purpose of the build method in flutter in flutter the build method is required method that is called by the framework to build the user interface of a widget so the purpose of the build method is to describe a how a widget should look and behave based on its current configuration and state the build method returns of widget tree which is a hierarchy of the widgets that describes the user interfaces of the widget so the widget 3 is then used by the framework to layout and paint the widget on the screen now this built method is called whenever the state of the widget changes or when the widget needs to rebuilt from any other reasons for example if the widgets configuration changes such as as its size or the color the build method will be called to update the widget's appearances so it is important to note that the build method should be a pure function meaning it should not have any side effects and should only depend on the widget's configuration and State so this is because the build method can be called multiple time during the lifetime of the widget and any side effects could lead to unintended Behavior so I hope you understood the explanation now let us see a sample answer so here the build method in flutter is responsible for creating and updating the UI of a widget this build method is called when the widget is first created and again whenever the widget State changes now if you look at the ninth question what is the purpose of init State method in flutter in flat arm the init State method is a life cycle method that is called when the stateful widget is inserted into the widget's tree for the first time the purpose of the init State method is to initialize the state of a widget which can include the setting default values initializing variables and subscribing to streams now let's see some of the common use cases of the init State the first one is initializing the variables you can initialize any instant variable of the widget inside the init State method for example if you have a counter variable that you want to start at 0 and you would initialize this has the counter is equals to Zero by using in its state you can initialize the count as equals to zero methods also the next one is the setting up the listeners so if your widget needs to listen to any streams or change notifications you can set up these listeners inside the init State method for example if you want to listen to stream that updates the UI every time new data is received so you would set up this listener like stream subscription which is equals to my stream Dot listen where you will give the data as a parameter over here then you will have a set State method that is called so in such a way you can also set the listeners there then we have a fetching data if your widget needs to fetch data from any API or a database so here you can do this inside the init State method for example you can use the HTTP package for fetching data from any API and update the widget State when the data is received so you need to understand it is very important to note that any heavy computation or long running operation should not be performed inside the init State method as it can slow down the app's performance and cause it a freeze Zone instead you need to perform these kind of operations asynchronously for example using the future dot display method of the async or a weight keywords so if I want to make it simpler and I want to give you a sample answer then the init State method in flutter is called when a stateful widget was created and it is used to initialize the widget state so this method is typically used to fetch data from an API or to set up animations or other long running tasks so I hope you understood with that question now let's move on to the next question that is what is the purpose of set State method in flutter in flutter the set State method is used to update the state of a widget and trigger a rebuild of which its user interface so the purpose of set State method is to tell flutter that the state of widget has changed and that the widget needs to be rebuilt with the updated state so here let us see how set State works the first thing when you call this set State the flutter Schedule C rebuild of the widget the next thing is during the rebuild the flutter calls the built method of the widget which creates a new widget tree based on the updated state and the next thing is the flutter compares the new widget tree with the old widget tree a place only the necessary changes to the UI so this is also simply called the reload method so here I have a code so if you look at this code so in this example the counter is a variable that holds the current value of the counter so whenever the user Taps The Floating Action button over here the increment counter is called which increments the counter and the calls set State method to update the UI here the build method is then called again with the updated counter value and the UI is rebuilt to show the new values so if we want to make it simpler to answer the set State method in flutter is used to update the state of the stateful widget which in turn triggers a rebuild of the widget UI so this method should be called whenever the state of the widget is changed then we have the 11th question what is our future inflator a future is a way of representing a value or the error that may not be available at but this will be at the some point in the future a future represents a computation that may take some time to complete such as loading the data from the database or making an API call so now let's see how it works so it is when called a function that returns a future it immediately returns a future object also so the future object is represents the result of the computation so which may not be available it you can also use the then method of the future to register a callback that will be called when the computation completes and then results in the available you can also use the catch error method to register a callback that will be called if the computation fails with an error so if you look at this code here here we have this get item from the database so this is a function that returns a future list item the then method is used to register a callback that will be called when the list of item when the database query completes successfully the catch error method is used to register a callback that will be called if the database query fails with an error you need to note that the async and a weight keywords are used to write the asynchronous code in a more synchronous style the await keyword is used to pass the execution of the function until the future completes and the async keyword is used to make the function as asynchronous method so simply in shutter a future is an object that represents a computation that has not yet completed so it is also typically used for the asynchronous tasks such as the network request or the file input output operations then we have the next question what is stream in flatter a stream is a way of representing a sequence of asynchronous events a stream provides a way for your code to receive and respond to the event as they occur rather than waiting for a computation to complete so how does it work a stream represents a sequence of events such as the mouse is clicked or the timer takes or the data received over a network connections so here you can use the listen method of this stream to register or callback that will be called each time an event is received the Callback will receive the event has a parameter and can perform some actions in the response to the event so if you take a look at this example over here here the counter controller is a stream controller here so that is used to send the event to the Stream so when the user clicks on The Floating Action button that is your handle button clicked is called so which sends a 1 to the stream using the sync dot add method so here you can see right here the stream Builder widget is used to build the UI based on the event received from the Stream the stream parameter is set to the countercontroller dot stream which is the stream that we want to receive the events from here the initial data parameter is set to 0 which is the initial value of the counter the Builder function is called each time a new event is received from a stream and is passed a snapshot object that contains the latest value of the stream the Builder function returns a text widget that displays the current value of the counter so let us make this more simpler the inflator or stream is a sequence of asynchronous events that can be listened to and processed in the real time streams are commonly used for the processing data that is continuously updated such as the data from a sensor or a database then we have the next question that is what is the purpose of the material app widget in flutter in flutter the material app widget is used to define the basic material design that is visual elements and the behavior of your app so it's typically the root widget of your app and it is used to set the app's title theme home page and roots so let us see some of the key features and benefits of using the material app widget we have the app bar and title here you can specify an app bar and title using the app bar widget so which is built into the material app so this provides a consistent visual event across your app and helps user identify your app so that is like your heading of the app so then we have the navigations the material app provides a default navigation system that allows user to move between the screen in your app so here you can Define your app's Roots using the root property of the material app then we have the theming the material app allows you to define a theme for your app using the theme data class this allows you to custom the visual style of your app such as the color typography and shapes then we have the localization the material app provides the built-in support for localizing your apps text and UI elements then we have the accessibility here using material app includes the built-in accessibility feature such as the support for the screen readers and the ability to custom the text size so if I want to make it simpler or if I want to give you a sample answer then the material app widget in flatter is convenience widget that provides Common App level features such as the navigations theme and localizations it is typically used as a root widget of the flutter app so as a beginner it is very important to know what is material app and what features does it has so once we have seen with the material app now we will move ahead and see the question from the scaffold now let's see what is the purpose of this scaffold widget in flutter so this scaffold widget is a basic visual layout structure for your app screen or the page so it can provide a container for the app bar or the navigation drawer Floating Action buttons and button navigations bar and other common UI components that are typically used in your mobile apps so if you look at the features same like the material app here we have the app bar here these scaffold widgets includes a built-in app bar that can display a title icon and actions such as the search or the settings here the app bar can also customized to include the additional elements such as the tabs or back button or a menu then we have the body content here this scaffold which it provides a container for the main content of your screen so which can be a single widget or a widget tree this content can be scrollable or non-scrollable or even Outlet on the top of other elements such as The Floating Action buttons then we have the floating action button here the scaffold widget can display a floating action button that is your Fab so that performs a primary actions that happens on the screen such as the adding a new item or opening a search dialog here this Floating Action button can be customized with the icon text or other elements even so after that we have the bottom navigation bar in this scaffold here this widget can also display a bottom navigation bar that allows the user to switch between the different screens or the tabs within your app so here the bottom navigation bar can be customized with the icons text or both then we have the drawer here this scaffold widget includes a built-in navigation drawer that can slide in from the left side of the screen so this drawer contains the links or the button to other screens or the functions within your app so if I want to give you a sample answer then those scaffold widget in flutter is a basic framework for the building app UI so it provides a default app bar bottom navigation and floating action button as well as the ability to easily add and customize the additional UI elements so such as the drawer and the snack bar then we will move on to the last question in the beginner section what is layout widget in flutter so in flatter a layout widget is a widget that arranges its child widgets in a specific way following a certain layout algorithm a layout widget is used to create a visual structure of your app by determining the size position and Order of the widget that make up your UI so there are several built-in layout widgets available in flutter such as the column row stack expanded then you have the flexible list view grid View and many more so each of these layout widgets has a different purpose and behavior and it can be used to achieve the different type of layouts and you need to understand that the layout widgets are the building blocks of your app UI and understanding how to use them effectively is a key to create a well-designed and responsive user interfaces in flutter so let me give you a sample answer in flutter a layout widget is a widget that is used to position and size other widgets with a parent widget examples of layout widget includes the row column and stack this widget provides different way to arrange child widgets and control their placements and sizing within the parent widget now that we have done with the beginner level shutter interview questions now let us move ahead and see the intermediate flutter interview questions so the first question in the intermediate level is what is flutter widget tree and how does it work here the flutter widget tree is a fundamental concept that the flutter represents the user interfaces of a flutter app so in flutter everything is witted right so from a small visual elements like button or text label to entire app itself here the widget tree is a hierarchical structure where each widget can have one or more child widgets the parent widget defines that the layout and the behavior of its child widget so here when a widget is added to the tree the flutter creates the corresponding element object that manage the widget State and it handles the rendering of the widget on this screen so whenever the state of the widget changes such as the user interactions or change in data so here the flutter updates the widget tree to reflect those changes this process is called reconciliation here this flutter efficiently updates only the part of the widget tree that have changed which results in the smooth and the performant user interfaces and the widget tree is also important for managing the lifecycle of a flutter app for example when a new screen is displayed a new widget tree is Created from that particular screen and the old tree is discarded here understanding how the widget tree works is essential for developing a high quality flutter apps so if I want to make it simpler for answering in the interview though widget 3 is a foundational Concept in flutter so that is our main answer that you need to tell so adding on that it represents the hierarchy of the widget that makes up your app user interfaces and each widget has a parent widget except for the root widget which is the top level widget of your app so when a widget needs to update or rebuild flutter transfers the widget tree to determine which widgets needs to update and then updates it accordingly so I hope you understood what is widget tree so let's move and see the next question the difference between list View and grid view in flutter great View and list view are two of the most commonly used widget in the flutter for displaying a list of data the main difference between the list and the grid view is the way they layout their child widgets so if you take out the main difference of the list and the grid view is where the list view is used to display a list of items in a single vertical column so it is supported both horizontal and the vertical scrolling here the children of the list view are arranged vertically and each child takes off the full width of the list View and you need to understand that the list view is ideal for displaying a long list of items so that do not require complex layouts now in the other hand if you take a look at the grid view it is used to display a collection of items in two dimensional grid so it supports both horizontal and vertical scrolling the children of the grid are arranged in rows and columns and the each child can take off a specified amount of space in the grid and the grid view is ideal for displaying a collection of items that requires a more complex layout such as the image with the captions so let us take a look at some of the other differences of the list and the grid view whereas you take a list view can display a list of items of varying Heights whereas the grid view requires that all the items have the same height and width and list view is more efficient than grid view so when displaying a long list of items because it only renders the items that are currently visible on the screen so that is why the list view is more efficient than the grid View and grid view supports multiple types of scrolling including the scrollable columns and rows and also it is used to create a staggered grid where items are arranged in a grid but can have varying Heights or widths so in general if I want to conclude list view is used for displaying a simple list of data while grid view is used for displaying more complex layouts of grid data list view is a widget that displays a scrollable list of widgets while grid view is a widget that displays a scrollable grid of widgets so the main difference between these two are the way that they arrange their child widgets so the list view arrange their child widget vertically in a single column whereas grid view arranges its child widgets in a grid either horizontally or vertically so let us move on to the next question with that let us see what is this stream Transformer in flutter so basically the stream Transformer is a class inflator that allows you to transform a stream of data from one form to another form so it takes an input stream a plays a transformation function to each event in the Stream and it produces an output stream of transformed events so let's move on to the next question there is how do you handle user input in flutter so this is simple so there are several ways to handle user input in flood so it depends on the type of input and the widget that you are using in the flutter project for example you can use the on pressed property of a raised button widget to handle the button pressed so now the race button has changed to elevated button or the on change property of a text field widget to handle the change to the text field so similarly you will have a lot of user input that you can handle with the other properties so just that you need to go and explore a lot of properties or lot of projects so that you will get a clear understanding of how you need to use a property for a particular method or a class so I hope you understood let us move on to the next question what is a provider in flutter and how do you use it so provider is a state management library in flutter so that allows you to share data between the widgets efficiently and in a way that is easy to maintain so here this works by providing a simple source of a truth for your app state so which can be accessed by any widget in your app so to use the provider you typically Define a change Notifier so this class that represents your app's State and then wrap your apps widget in the change Notifier provider widget to make the state available to the other widgets so this is how the provider works in the flutter so let us move on to the next question what is a flutter plugin and how do you create one shutter plugins are the packages that provides a way to access the platform specific functionalities such as accessing the device's camera or sending the push notifications so these letter plugins are typically written in the language specific to the Target platform such as for example the Java or kotlin for the Android or Swift or the object C for the iOS and it communicates with the flutter app using a platform Channel so to create a flutter plugin you have a few steps create a new flutter plugin project using the flutter create template plugin command so after this you need to implement the plugin functionality in the Target platform language for example I told you no Java and kotlin or the Swift or the object C and then you need to create a platform channel that allows the flutter app to communicate with the plugin code moving ahead you need to implement the plugin functionalities in the flutter app using the platform Channel after that you need to publish the plugin to the package manager such as the pub.dev or for other developers to use it so this is how you will create a flatter plugin so I hope you understood let us move on to the next question here how do you implement animations in flutter flutter provides a powerful framework that allows you to create a complex animations in your app so you can use this animation Frameworks to animate any property of a widget such as its position size opacity or color so there are General steps to implement the animation in flutter like creating an animation controller here an animation controller is used to drive the animations by specifying the duration like start time and the value range of the animations so you can create an animation controller by calling just an animation controller into the parameters and you can pass the duration and you can sync the argument over there and then you need to create an animation here an animation is a value that changes over time right so usually a linearly are using a curve so you can create an animation by calling the tween Constructor and passing it to the start and the ending value of the animations then you can pass the twin object to the Controller driver this method to create the animation object then after that you need to wrap the widget in an animation widget so this is a special widget that automatically rebuilds itself whenever the animation values changed so you can wrap the widget that you want to animate in an animated widget and pass it in the animation object then after that you need to animate the widget property also so here you can use the value of the animation object to animate any property of the widget for example you can use the transform dot translate so this widget is to animate the position of the widget or you can use the animated opacity widget to animate the opacity of the widget so it is as simple as that so you can use whatever animation you want to use in your Shutter application as your wish so with that let's move on to the next question what is the purpose of the Navigator widget in the flutter the Navigator widget is used to manage the navigation stack in a flutter application so it allows you to push on new routes onto the Navigator stack that pops the root of the stack and it controls the transitions between the screens here the Navigator widget also provides a method for passing data between the screens and for returning the data from a screen to its parent screen so this is the use of the Navigator so in simple words the Navigator is just a widget that is managed to navigate the stack in the flutter application it is just a move or it is just to tell the where you need to go after you click a button so I hope you understood that so let's move on to the next question what is the difference between a package and a plug-in in flutter so in flutter the package is collection of Dart code so that can be shared and reused across the multiple flutter projects so as you all know a flutter is written in the dark language so if a package in the flutter is also written in the dart code a plugin on the other hand is a package that provides the access to the platform specific functionalities such as the camera or the location service as I said in the previous question so these can be used in a cross-platform way for using the platform channels while packages can be purely Dart based and plugins typically requires native code development for Android and it can also used in the iOS in the additional to the dart code so with that we have completed the intermediate level flutter interview questions now let us move on to the advanced flutter interview questions so where we can at least have an idea of how a advance level question will be asked and you can prepare according to it so here I will be giving you only a brief answer so that you can understand the type of question will be asked in the advanced level interview questions so let us move on to the first question in the advanced level what is flutter engine and how does it work the flutter engine is a low level Graphics rendering and layout engine that is responsible for the rendering the UI of your flutter project so in simple words these are the engine in a low level Graphics rendering and it also has a layout engine that is responsible for the rendering your UI for the flutter applications and it is also used as a portable graphic engine called your skia to draw the graphs which allows the flutter to run on the multiple platforms such as the Android iOS and web so the engine also manages the animation and the layout of your user interface elements so this is what is your flutter engine is so if you look at the second question in the advanced level what is the purpose of the flutter inspector and how do you use it so briefly the flutter instructor is a tool that allows the developers to inspect the bus and the UI of your flutter application and it provides the information about the widget hierarchy properties and constraints and also it allows the developer to modify the widget Tree in real time to use the flutter inspector developers can launch it from within the flutter IDE or by running the flutter inspect command in the terminal also so I hope you understood so that let's move on to the next question how do you optimize the performance of a flutter application to optimize the performance of the flutter application developers can use several techniques such as minimizing the number of Widgets or using the constant Constructor for widgets that do not change and you can use the flutter Dev tools to analyze the performance issues and also using the asynchronized programming to avoid the blocking the UI thread additionally developers can also use the flutters widget tree to effectively manage the state of the application so if you look at the fourth question in advance level what is flutter's rendering Pipeline and how does it work letters rendering pipeline is responsible for updating the UI of a flutter application so it works by first building a widget tree based on the current state of the application then the engine uses the a widget tree to generate a render object tree so it is a low level representation of the UI elements finally the engine draws the UI by transversing the rendered object tree and it generates the necessary graphic commands then we have a question like what are some best practices for managing the state in a large flutter application so some of the best practices to managing the state in a large flutter application including using the stateful widget only when necessary because it always re-renders and it draws a new screen over in the flutter application so it always reruns whenever the stateful widget is called so that is why you need to use whenever it is necessary and you need to separate the UI from the state management also using the block pattern to manage the state and using the reactive programming techniques to efficiently update the UI so these are the some of the best practices to manage the state in the large flutter applications then we have the next question what is the purpose of the flutter driver and how do you use it for the automated testing the flutter driver is a tool that allows the developers to write automated tests for flutter applications so it provides a set of apis that developers can use to stimulate the user interactions such as tapping on buttons or entering text or scrolling to use the flutter driver developers can write the test scripts in Dot and it can run them using the flutter test Runner so let us see the next question over here what are some techniques for implementing the responsive designs in flutter so some of the techniques to implement the responsive design and flutter including using the media query to get informations about the device's screen size using the layout Builder widget to create the layouts that adapts the screen size so and then using the flex and expanded widget to create the flexible layouts and using the aspect ratio widget to maintain the aspect ratio of your user interfaces elements so these are the techniques that you need to implement whenever you need to have a responsive designs in the flood applications so with that let us move on to the next question so what is flutter's architecture and how does it compare to other app development architectures letter follows the reactive programming Paradigm and uses a unidirectional data flows architecture called the flutter architecture which is inspired by the model view update pattern so this architecture is composed of three main parts that is the model and the view and the update function so if you take a look at the model then this is a data layer of the application that represents the state of the app and also it includes all the data and logic that are required to maintain the state of the application then if you take a look at the view then this is the presentation layer of the application that displays the user interfaces it also includes all the widgets that are required to display the user interface and receives input for the user and then we have the update function so this is a control layer of the application that manages the state of the application but also it includes all the logic that updates the model and it rebuilds The View based on the changes in the model so whenever you compare to the other development architecture the flutter architecture has some of the similarities and differences so when you take a look at the model view controller so this is a traditional architecture that separates the application into three parts that is the model The View and the controller and the controller is responsible for the managing the communication between the model and the view so in comparing the flutter and the architecture combines the controller and the model into a single update function so then we have the model view press enter this is another traditional architecture that separates the application into three parts same like the model view and the presenter here the presenter is responsible for updating the view and handle the user input In the comparison of the flutter architecture the presenter and the model input is a single update function then finally we have the model view view model that is your mvvm so this is a modern architecture that separates the application into three parts the model The View and the view model The View model is responsible for updating the view and the handling user input so in comparing the architecture combines The View model and the model into a single update function in overall if I want to tell the flutter architecture is a modern and efficient architecture that simplifies the development of complex and reactive user interfaces so it also offers a straightforward and predictable data flow and is well suited for building the scalable and maintainable applications so let us move on to the ninth question what is the purpose of the flutter plugin registry and how do you use it so in brief the flutter plugin registry is a repository of plugin developed by the community that extends the functionality of letter the purpose of registry is to provide a centralized location where developers can find and download the plugins that can be used in their flutter project the plugins can provide access to Native devices features such as the camera GPS and storage as well as the third party services such as the Google Maps and the firebases to use a plugin from the registry you first need to add it to your flutter project by specifying it as a dependency in your projects pubspect.yaml file so once you have added the plugin you can import it into the code and start using its functionality so this is how you will use the plugin registry so with that let us move on to the last question in the advanced section so how do you implement the platform specific functionalities in the flutter application flutter provides a mechanism for accessing the platform specific functionality through the platform channels platform Channel all of your flutter app to communicate with native code running on the devices platform such as the Java code running on the Android device or Swift Code running on the iOS devices to implement the platform specific functionalities in a flutter app you first need to define a platform channel that describes the method signature for the native code you want to call then you need to implement the corresponding native code on each platform and register the Channel with the flutter engine finally you can use the platform channel in your flutter code to call the native code and access the platform specific functionality for example if you want to access the device camera in a flutter application so here you could Define a platform channel that provides a method for starting the camera and also you would then implement the corresponding Java or Swift code to start the camera on each platform and then register the Channel with the flutter engine in your flutter code then you could call the platform Channel method to start the camera and receive the camera output so with that we have come to an end of the advanced level flutter interview questions then we have the five set of scenario based interview questions so let us see one by one so let us take a scenario where you need to build a flutter app that needs to display a list of items so how would you implement this feature in flutter so how would you answer this so simply tell to display a list of items in a flutter app we can use the list view widget right do you remember that in initially I have mentioned the list View and grid view so in that you can take some of the points over there and you can include here for the list view then here we have the list View the list view is a scrollable list of a widget that are arranged linearly right so this can be used to display a large number of items without taking up too much screen space so we can also use the grid view so this widget is to display an item in a grid pattern so it also allows us to create a grid of items with a fixed number of columns or with a variable number of columns depending on the device sizes so this is how you will take the answer from the list and the grid View and you can make up your own answer so it is just a matter that you need to understand the concept properly so I hope you understood this scenario based question so let us move to another one where you need to build a flutter app that needs to handle the user input from the text field so how would you handle this in the flutter so to handle the user input from a text field in flutter you can use the text edit controller class so we can create an instance of text edit controller and pass it to the text field widget using the controller property here the controller allows us to get the text entered by the user and to clear the text field so let us take this question so you are building a flutter app that needs to display a pop-up dialog box so how would you implement this feature in the flat so simply tell that to display a pop-up dialog box in flutter we can use the show dialog method so this method displays a model dialog box that overlays the current screen so we can pass our widget to the show dialog method to specify the content of the dialog box we can also add buttons to the dialog box using the flat button or raised button widget so now instead of race button widget you can also use the elevated button widget so that would also work with it fine so then we have another question so here you are building a flutter app that needs to navigate to a new screen when the user Taps on a button so how would you handle this inset to navigate to a new screen when the user tabs on a button in flutter then we can use the Navigator class here we can create a new route using the material page root class that passes it to The Navigators push method here the material page root class takes a widget has an argument that represents that the new screen to be displayed so when the user Taps on the button we can call The Navigators push method and pass the new route to it so this will display the new screen and it allows the user to navigate back to the previous screen using the back button so this is how you will navigate to a new screen so if you take a look at the final question in our interview session is consider you are building a flutter app that needs to fetch date of Raman API so how would you handle this in flutter to fetch the data from an API influctor we can use the HTTP package so that is the basic package so if you are starting has a new so you can start with the HTTP for fetching an API data so we can create a new instances of HTTP client and you can use its get or post method to fetch data from the API then we can then pass the responses using the dart converter package and then display the data into your app so to handle the asynchronous data we can use the future Builder widget to display a loading indicator while the data is being fetched and then display the data once it is available so we can also handle the error and exceptions by using the try catch block around the API calls so we have done with the interview questions so let us see some of the tips to crack your flutter interview so whenever you are attending any interview or any technical interview specifically you need to understand the basic concepts so the first thing here is to familiarize yourself with the basics so make sure you have a good understanding of the basic concept of flutter including the widget State Management and asynchronous programming layouts Navigators app bar Etc so first you need to practice the code and then you need to understand those codes what does it does and you need to understand the properties functionalities of the basics first then you need to practice the code so one of the best way to prepare for the flutter interview is to practice code so create simple apps Start experiment with the different features to gain Hands-On experiences or you can fetch some of the widgets or other features from the other app and you can use it for your own app so by doing these practices in the flatter applications then you can have a wide range of understanding of what widget or what layout should you use after what so after that you need to review a sample interview questions that can help you to get a sense of what to expect during the interview like you have come to this session right so you can have a brief understanding of what kind of questions will be asked in the interview and you can find the sample question online or by speaking with other who have gone through the process or who has experience in the flutter domain so you will have an idea of how the interview process goes and you can have a good knowledge of how to answer those interviews then you can showcase your portfolio so if you have a portfolio of platter applications so be prepared to Showcase them during the interview this will give the interviewer a chance to see the skills and experience in action so they will understand how skilled you are and how your presentation skills are there so this can help the interviewer to pick you as the first priority then you have to research about the company so it doesn't matter what company you are going first you need to understand about the company and you need to understand what kind of products they do have and what kind of services they do provide so you need to learn about their product services and Mission so this will help you to understand how skill and experience aligned with their needs so that you can prepare more about their company and you can go and give the interview so that you can get selected among the other competitors so while showcasing your skills you need to be very confident so that it shows the interviewer that you are very passionate about the flutter and you are excited to work with them and their team so it is very important to show them that you are an energetic person and you have many skills within you then finally you need to ask questions so be prepared to ask questions during the interview so this can show the interviewer that you are very engaged and interested in the position so ask about the company culture and the team that you are working with and the projects that you will be working on so with this you will have a good understanding about your team as well as the project that you're going to work so that the interviewer will also have a good understanding about your skills and your engagement into the project so by following these interview questions and the tips I have given you can develop the skills and knowledge needed to become a successful shutter developer and join your dream company so remember becoming a flutter developer takes time dedication and hard work and also it requires a combination of Technical and soft skills so I hope you will be a better flutter developer in the future we edureka wish you all the very best for your upcoming interviews so if you are interested in getting in flutter online courses certification then you can check out the link that is given in the description box so if you like watching videos like this and we have lot more videos coming on this topic so don't miss out the latest and trending topics that are coming in this channel so hit the Subscribe button and hit the Bell icon to never miss any updates from Erica so let's see you in the next video Until Then happy learning I hope you have enjoyed listening to this video please be kind enough to like it and you can comment any of your doubts and queries and we will reply them at the earliest do look out for more videos in our playlist And subscribe to edureka channel to learn more happy learning

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Views: 51,882

Keywords: yt:cc=on, flutter interview questions, Flutter interview questions and answers, Flutter interview questions beginner, flutter interview questions for beginners, flutter interview preparation, Flutter interview questions intermediate, Flutter interview questions advanced, Tips and tricks to crack flutter interview questions, Flutter scenario-based interview questions, Flutter training, edureka Flutter, Edureka, flutter interview, Flutter interview questions for freshers

Id: mwU0xr2jhIU

Length: 71min 51sec (4311 seconds)

Published: Fri Apr 07 2023