AngularJS is a JavaScript framework used for creating single web page applications. It allows you to use HTML as your template language and enables you to extend HTML’s syntax to express your application’s components clearly.
2 What are some ways to improve performance in an AngularJS app?
There are two methods that are officially recommended for production: enabling strict DI mode and disabling debug data.
Enabling strict DI mode can be achieved by being set as a directive, like so:
Disabling debug data can be achieved with the $compileProvider
, like so:
Some other popular enhancements to performance are:
$httpProvider
use applyAsync
2 Which hooks are available in AngularJS? What are their use cases?
An AngularJS component can implement lifecycle hooks, which are methods to be called during a component’s life. The following are hook methods can be implemented in AngularJS.
Question: List out the Directives in AngularJS?
Answer: ngBind, ngModel, ngClass, ngApp, ngInit, ngRepeat
1 How can you make an ajax call using AngularJS?
AngularJS uses the $https:
to make ajax calls. The server will make a database call to get records. AngularJS uses the JSON format for data.
Question: Explain the ng-init directive
Answer: The ng-init directive initializes an AngularJS Applications data. It is used to put values to the variables to be used in the application.
For example, in the below code we have initialized an array of countries using JSON syntax to define the array of countries.
32) How can you set, get, and clear cookies in AngularJS?
You can use:
Service method in AngularJS helps you to define service and method to it. In the following example, we have injected a simple addition service, which adds two numbers.
62) What is the Ahead of Time Compilation?
Angular AOT (Ahead of Time) is a compiler that converts your angular HTML and typescript code into the JavaScript code.
1 What is the digest phase?
The digest cycle is crucial for data binding. It essentially compares an old and a new version of the same scope model. The digest cycle can triggered automatically or manually with $apply()
.
With every digest cycle, every scope model is compared against their previous values. When a change is found, the watches of that model are fired, and another digest cycle is initiated until it is stable.
This is not needed if we only use core directives. If there are any external changes to the code, the digest cycle needs to be called manually.
56) List out the difference between Angular Component and Directive
Component | Directive |
Angular component is a directive that enables you to utilize the web component functionality throughout the application. | Angular directive is a technique by which we attach behavior to the elements. |
It helps you to divides your application into smaller components. | It helps you to design the reusable components. |
It can define pipes | It cannot define pipes. |
ECMAScript (European Computer Manufacturer’s Association) is a standard for scripting languages. JavaScript uses ECMAScript as a core language. Developers can take help of it for writing client-side scripting on the world wide web and or server applications and services. ECMAScript has numerous features like functional, prototype, dynamic, and structured features.
47) Explain the auto bootstrap process in AngularJS
Angular initializes automatically DOMContentLoaded event or when you download angular.js script is to the browser.
After this, AngularJS find the ng-app directive that is the root of angular app compilation. When ng-app directive is found, AngularJS do the following steps:
1) load the module, which is associated with the directive,
3) Compile the DOM from the ng-app root element. This process is known as auto bootstrapping.