AngularJS Introduction
AngularJS is a JavaScript framework. It can be added to an HTML page with a <script> tag.
AngularJS extends HTML attributes with Directives, and binds data to HTML with Expressions.
AngularJS is a JavaScript Framework
AngularJS is a JavaScript framework written in JavaScript.
AngularJS is distributed as a JavaScript file, and can be added to a web page with a script tag:
<script
src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>
AngularJS Extends HTML
AngularJS extends HTML with ng-directives.
The ng-app directive defines an AngularJS application.
The ng-model directive binds the value of HTML controls (input, select, textarea) to application data.
The ng-bind directive binds application data to the HTML view.
AngularJS Example
<!DOCTYPE html>
<html>
<script
src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>
<body>
<div ng-app="">
<p>Name: <input type="text" ng-model="name"></p>
<p ng-bind="name"></p>
</div>
</body>
</html>
Try it Yourself »
Example explained:
AngularJS starts automatically when the web page has loaded.
The ng-app directive tells AngularJS that the <div> element is the "owner" of an AngularJS application.
The ng-model directive binds the value of the input field to the application variable name.
The ng-bind directive binds the content of the <p> element to the application variable name.
AngularJS Directives
As you have already seen, AngularJS directives are HTML attributes with an ng prefix.
The ng-init directive initializes AngularJS application variables.
AngularJS Example
<div ng-app="" ng-init="firstName='John'">
<p>The name is <span ng-bind="firstName"></span></p>
</div>
Try it Yourself »
Alternatively with valid HTML:
AngularJS Example
<div data-ng-app="" data-ng-init="firstName='John'">
<p>The name is <span data-ng-bind="firstName"></span></p>
</div>
Try it Yourself »
You can use data-ng-, instead of ng-, if you want to make your page HTML valid.
You will learn a lot more about directives later in this tutorial.
AngularJS Expressions
AngularJS expressions are written inside double braces: {{ expression }}.
AngularJS will "output" data exactly where the expression is written:
AngularJS Example
<!DOCTYPE html>
<html>
<script
src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>
<body>
<div ng-app="">
<p>My first expression: {{ 5 + 5 }}</p>
</div>
</body>
</html>
Try it Yourself »
AngularJS expressions bind AngularJS data to HTML the same way as the ng-bind directive.
AngularJS Example
<!DOCTYPE html>
<html>
<script
src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>
<body>
<div ng-app="">
<p>Name:
<input type="text" ng-model="name"></p>
<p>{{name}}</p>
</div>
</body>
</html>
Try it Yourself »
You will learn more about expressions later in this tutorial.
AngularJS Applications
AngularJS modules define AngularJS applications.
AngularJS controllers control AngularJS applications.
The ng-app directive defines the application, the ng-controller directive defines the controller.
AngularJS Example
<div ng-app="myApp" ng-controller="myCtrl">
First Name: <input type="text" ng-model="firstName"><br>
Last Name: <input type="text" ng-model="lastName"><br>
<br>
Full Name: {{firstName + " " + lastName}}
</div>
<script>
var app = angular.module('myApp', []);
app.controller('myCtrl',
function($scope) {
$scope.firstName= "John";
$scope.lastName= "Doe";
});
</script>
Try it Yourself »
AngularJS modules define applications:
AngularJS Module
var app = angular.module('myApp', []);
AngularJS controllers control applications:
AngularJS Controller
app.controller('myCtrl',
function($scope) {
$scope.firstName= "John";
$scope.lastName= "Doe";
});
You will learn more about modules and controllers later in this tutorial.
