Explore topic-wise InterviewSolutions in .

Because Ionic 1-3 is heavily reliant on Angular. The same compiling options that were available for Angular were also accessible for Ionic.

• JIT is an abbreviation for "just in time compiler". It is a sort of compilation in which the application is compiled in the browser at runtime.
• AOT is an abbreviation for "AHEAD of time compiler”. It is a sort of compilation in which the application is compiled in the build time.
• It will be JIT if we only use the ionic Cordova build platform (android or iOS). It will use AOT if we use the prod flag, Ionic Cordova builds platform --prod.

When compared to AOT, SOFTWARE designed with JIT is slower. However, AOT requires greater compilation time than JIT. So UTILISE JIT for quick checks and AOT for final deployment.

In the mobile development market, Ionic developers are in high demand. Prepare with these Ionic FRAMEWORK interview questions to ace your next Ionic interview and pursue a career as a Mobile Application Developer, Frontend Developer, and, of course, an Ionic developer. We are certain that this article on Ionic interview questions has significantly increased your understanding of Ionic concepts. You will be able to confidently crack any relevant interview if you have a firm GRASP of all of the questions presented here. Answering questions about Ionic CLI, distinct components in Ionic, and how to establish a new project using Ionic CLI will be easier if you study these Ionic framework interview questions and answers well.

Recommended Interview Resources:

• Android
• iOS
• React Native
• Flutter
• Appium
• Mobile Testing

Network calls are one of the key areas that will have a significant impact on the app's performance. To improve the app's performance, it should be fine-tuned to the highest level of accuracy.

• If two different components are attempting to make HTTP calls to the same URL, it is preferable to make a single call and transmit data to both components than to make two separate HTTP calls. The requested action is completed in a MATTER of seconds.
• The best method to do this is to use a root component. A shared root component should be used by all components making HTTP calls. This KEEPS note of URLS that were requested a few seconds ago, and if they are requested again, it can add a SMALL delay before SENDING the result to both components.

• Ionic has been reliant on Angular framework components since its inception as a utility for Angular USERS. Ionic became framework-agnostic in version 4, which means it is no longer dependent on Angular. The move was made possible through the use of web components and the PROMOTION of Ionic's command-line interface.
• Web components are a collection of features that make use of common APIs that are natively supported by practically all mobile browsers today. As a result, they may be DEPLOYED on any mobile DEVICE or utilised to develop desktop applications using the Electron framework, such as Progressive Web applications (PWAs). The use of web components with Ionic also allows for the use of any framework.

Security is a typical concern while developing HYBRID applications, as long as your application can be reverse-engineered.

• Ionic CLI has had built-in code uglification since version 4, which is a typical approach for making code difficult to read by hackers. However, you should be aware that there is no code uglification when using Angular CLI or previous versions of Ionic. Your programmers will have to uglify the code themselves.
• A man-in-the-middle attack is ONE of several ways to compromise what's going on with your mobile application or PWA. What difference does it make? Because, in essence, your Ionic application is a web page that runs on the device. The crucial point to remember is that Ionic connects with the backend via standard HTTP calls. As a result, you'll want to apply the same security protections to your Ionic application that you do to your website, such as using HTTPS instead of HTTP.
• Developers can include CUSTOM or user-provided content in components like ion-alert. This content, which can be plain text or HTML, should be regarded as untrustworthy. Before doing anything else with any untrusted information, it's critical to sanitise it. Using innerHTML without sanitization, for instance, presents an attack vector for bad actors to insert malicious material and potentially conduct a Cross-Site Scripting attack (XSS).  Ionic includes basic sanitization methods for the components it offers, but it is up to the developer to ensure that all DATA is sanitised for user-created components.
• If an attacker finds a flaw in an application's code (for instance, a third-party API call or a JavaScript package), they may find a way to exploit it such that malicious code is executed instead. The Content Security Policy (CSP) META tag was created to aid in the prevention of such attacks by specifying which network requests are permitted and where assets are loaded from. You'll observe that Ionic apps for iOS and Android often use Cordova's Network Whitelist Plugin to protect webviews that don't support CSP from cross-site scripting.

Ionic Native is a TypeScript wrapper for Cordova or PhoneGap plugins that allows you to integrate any native feature into your Ionic project. With the help of Ionic Native, we can quickly integrate any of the Cordova plugin communities into an Ionic APPLICATION. One of the BENEFITS of being an Ionic native is that you can create better code. We can also utilise Cordova plugins without Ionic Native, but Ionic Native adds types to these Cordova plugins via wrapper classes, allowing us to EMPLOY INTELLISENSE and code suggestions. This keeps you from making mistakes and allows you to DEVELOP codes faster and more effectively. The Ionic Native directory is regularly updated with new plugins.

• Views are cached by DEFAULT to increase efficiency. The element of a view is left in the DOM when it is navigated away from it, and its scope is separated from the $watch cycle. When you navigate to a previously cached view, its scope is reconnected, and the existing element in the DOM becomes the current view. This also allows prior views' scroll positions to be preserved.
• CACHING can be TURNED on and off in a variety of ways. IONIC caches a maximum of 10 views by default, and not only can this be changed, but APPLICATIONS can also specify which views should and should not be cached explicitly. Caching can be turned off per view by setting cache: false in the state settings of the UI router. The$ionicConfigProvider may be used to specify the maximum number of cached views, but it can also be used to turn off all caching by setting it to 0.

Ionic Applications GIVE IOS and Android devices incredible stability. It has excellent performance, little maintenance, and requires less storage space to run new Ionic applications, among other benefits. HOWEVER, it has been noted that the Ionic Application does not run smoothly on older Android smartphones. In older Android devices, any application built USING the Ionic FRAMEWORK has been reported as non-working. Any Ionic application running on Android devices prior to version 5 has a number of difficulties, including low performance/non-performance, heavy maintenance, interfering with other applications, and so on. A crosswalk plugin must be created externally to run applications on older Android devices, which will help Ionic applications perform better on older Android smartphones.

• A capacitor is a cross-platform SOFTWARE that allows you to create web applications that work natively on iOS, Android, Electron, and the Web using a single code base. These applications are known as Native Progressive Web applications, and they are the next development after Hybrid applications.
• It is INTENDED to be a successor for Apache Cordova and Adobe Phonegap, DRAWING influence from other successful cross-platform technologies such as React native, but it is only focused on allowing MODERN web applications to operate on all major web platforms. Many existing Cordova plugins are supported by the capacitor in a backwards-compatible manner.
• Capacitor converts your web application into a platform-specific native binary. As a result, you'll spend a lot of time establishing and then building a mobile-friendly web app. Using Capacitor's plugins (such as Camera) or existing Cordova plugins with Capacitor's Cordova Compatibility, you'll communicate with the native platform UNDERNEATH. Capacitor or Cordova plugins are used to interact between the Web View and the native app. Plugins provide your web application access to native APIs like the camera, geolocation, and filesystem. The capacitor includes a number of JavaScript utilities that can help you make sure your apps operate on many platforms with the same codebase. To utilise them, first import Capacitor, then call the utility function you want.

An alert is a dialog that provides crucial information to the user in order for them to make a decision or ALLOWS them to select a specific action or a set of actions. Before resuming contact with the application, the user can dismiss it manually. It's a floating modal that should be used for short responses like password verification and minor application notifications, AMONG other things.

In an Ionic application, the alert controller is in charge of creating an alert. It creates an alert USING the CREATE() method, which can be customised by giving the alert option to the create() method.

Ionic Events is a publish-subscribe event system that may be used to send messages across multiple components and pages. To put it another way, it's a framework for TRANSMITTING and responding to app-level events across your entire app. Interactivity with users can be added VIA a variety of Ionic events. All of the Ionic events are EXPLAINED in the table below.

A splash screen LOOKS LIKE a start screen or a start-up screen. It's a graphical control element that includes an image, a logo, and the software's current version. The splash screen is simply a display screen that allows PEOPLE to look at something while the hardware is LOADING so that software MAY be presented to them. It commonly displays as a game or software begins to load.

IONIC hooks have three distinct life cycles, as listed below:

• ionNavDidChange: This EVENT is triggered when the nav's components have changed.
• ionNavWillChange: When the NAVIGATION components change, this event is triggered.
• ionNavWillLoad: This event is triggered when the navigation system is about to LOAD a component.

Ionic makes advantage of the Angular life-cycle events. These are the life-cycle events:

• ngOnInit: It is a one-time event that occurs during component initialization. It can be used to set up LOCAL members and make one-time calls to services.
• ngOnDestroy: This event is triggered SHORTLY before the view is destroyed by Angular. It's useful for things like unsubscribing from observables and cleaning up.
• ionViewWillEnter: When the component routing-to is going to animate into view, ionViewWillEnter is invoked.
• ionViewDidEnter: When the component routing-to has done ANIMATING, ionViewDidEnter is fired.
• ionViewWillLeave: When the component routing-from is about to animate, it fires the ionViewWillLeave event.
• ionViewDidLeave: When the component routing-to has done animating, it fires the ionViewDidLeave event.

There are a few more lifecycle events that would prohibit users from GAINING unwanted access.

• ionViewCanEnter: It is called before entering a view, lets you control whether or not the view can be managed by the user.
• ionViewCanLeave: This feature is activated before the user can leave a view and allows you to control whether the view can be left or not.

Routing GUARDS can be used to replace the above two events in Ionic 4.

Ionic Market is a marketplace for Ionic developers who want to use pre-built starters, THEMES, plugins, and other resources. Starters, Plugins, and Themes are the three SORTS of items available on the Ionic Market. The Ionic marketplace makes it simple to submit, buy, and download starters, plugins, and themes for your projects. It's a good site to sell and buy ionic items.

The Ionic Market is completely free to use, and there are no additional fees for these BESPOKE services. If you placed your add-on for SALES in the Ionic Market, anyone may sell it DIRECTLY via the market or refer to another marketplace.

Debugging is an important element of any development process. When it comes to Ionic, We can use Chrome or Safari to debug Android and iOS applications.

Android: Follow the STEPS below to debug an Android application in real-time.

• On Android Mobile, ENABLE developer mode.
• ionic Cordova can be used to execute the application on a real device. Run Android or ionic Cordova build Android to build the apk and transfer it to the phone.
• Connect your device to your computer USING a USB cable, then open Google Chrome and go to chrome:/inspect/#devices to see your phone and application name. There's an inspect button there.
• You'll be able to inspect the application and look at the logs now.

iOS: To debug an iOS application in real-time, follow the steps below.

• Execute the command ionic Cordova to run the application on the device. Build the application with ionic Cordova or run-ios To get the application on the phone, you'll need to build it on iOS and use Xcode.
• Now go to Safari -> Windows -> Developer Options to enable developer options.
• You may now debug the application in real-time by going to developer -> Your phone -> localhost.

IONIC doesn't have a camera API by default. We may utilise Cordova plugins in our APPLICATION because Ionic has a plugins architecture that is based on Cordova. The Ionic team has created a collection of Cordova extensions that include Angular wrappers, which can be OBTAINED at ngCordova.

To use Cordova plugins, we must use the Ionic command install <plugin name> to install the plugin. In some circumstances, the plugin's Angular module will also NEED to be added to your Angular application. We can use cordova-plugin-camera, which is accessible on GitHub, to contact the camera API to use a mobile phone's camera in an Ionic application. This plugin CREATES a global navigator.camera object with an API for taking photos and selecting images from the system's image library. 

Because IONIC is built on ES6 and TYPESCRIPT, your editors or IDE must be capable of supporting these new languages. The most common editors and integrated development environments (IDEs) for Ionic application development are:

• VISUAL Studio
• WebStorm
• Atom
• ALM (Application Lifecycle MANAGEMENT)
• Angular IDE by Webclipse.

The term "REFRESHING" refers to the process of updating the currently DISPLAYED PAGE so that the user may see the most recent content. To provide pull-to-refresh capabilities to a content component, Ionic provides the ion-refresher component. Ionic allows users to utilise touch to pull the page down from the TOP of a list of data to access more information. During the refresher's output EVENTS, the updated data should be adjusted. When the page has finished refreshing, execute the refresher's complete() function.

The following methods can be used to minimise the size of an Ionic app:

• FIRST, compress all of the relevant icons and images, then eliminate any that you don't want.
• Second, minify all JS and CSS files and MAKE the necessary changes to the index.html page.
• Third, get rid of any unnecessary external modules or Cordova PLUGINS that aren't in use. You can also eliminate unneeded code from the PROGRAMME, which will save you a lot of space.
• Finally, you can use the following command to shrink the app's size: ionic build android -PROD.

The @ionic/storage PACKAGE in the ionic framework has a storage module. We MAY use the storage module to hold key-value pairs and JSON objects in a safe and reliable manner. It has its own SET of constraints.

Storage engines come in a variety of flavours, and which ONE is ideal for you depends on the platform you're using. When executing in a native application context, SQLite is used for storage. Storage will use IndexedDB, WebSQL, and localstorage while operating on the web or as a Progressive Web App. The SQLite file-based database is the most stable and widely used, avoiding the drawbacks of alternative storage engines such as IndexedDB, WebSQL, and localstorage.

When we need to display a big AMOUNT of data in an Ionic application, the ion-infinite-scroll component comes in handy. Whenever the user scrolls a certain distance from the top or bottom of the page, this component allows information to be loaded into the app.

Every mobile application requires a technique to display a large amount of data with fewer clicks. In that instance, the infinite scroll is critical to their success. The infinite scroll component SERVES the same purpose that we WOULD if we were loading ten items on a page. Whenever the user scrolls down to the bottom of those items, it triggers a new data request. This request retrieves the next set of record entries to be integrated with existing ones. This procedure continues until the new data is no longer visible in chunks as the user scrolls. The news feed region of Facebook, Instagram, or Twitter is the finest example of an ion-infinite-scroll. When you reach the desired distance, the page AUTOMATICALLY loads fresh posts, and a loading spinner appears at the bottom of the screen.

You can utilise the localStorage and SESSIONSTORAGE APIs to persist DATA on the mobile phone because Ionic is an HTML5 framework. Because localStorage can only save strings, OBJECTS must FIRST be stringified before they can be saved. It's also worth noting that the MAXIMUM capacity for localStorage is 5MB. 

Ionic offers a platform service for obtaining information regarding the current device.

• All of the PLATFORMS linked with the device are returned by the platform method.
• It also indicates if the application is being seen on a tablet, mobile device, or browser, as well as the platform used, such as Android or iOS.
• Ionic applies CSS CLASSES to the <body&GT; tag when the application is loaded on the device. Ionic, for example, adds the platform-ios class to the <body> tag on iOS DEVICES.