Expressions are used for application data binding to HTML. Expressions are written in double brackets like {{expression}}. The behavior in expressions is the same as the ng-bind directive. AngularJS application expressions are pure javascript expressions and output the data they are used in there.
Use numbers
<p>Expense on Books : {{cost * quantity}} Rs</p>
Use string
<p>Hello {{student.firstname + " " + student.lastname}}!</p>
Use object
<p>Roll No: {{student.rollno}}</p>
Use an array
<p>Marks(Math): {{marks[3]}}</p>
Example
The following example will demonstrate all the above expressions.
The testAngularJS.html file code is as follows:
<html>
<title>AngularJS Expressions</title>
<body>
<h1>Sample Application</h1>
<div ng-app="" ng-init="quantity=1;cost=30; student={firstname:'Mahesh',lastname:'Parashar',rollno:101};marks=[80,90,75,73,60]">
<p>Hello {{student.firstname + " " + student.lastname}}!</p>
<p>Expense on Books : {{cost * quantity}} Rs</p>
<p>Roll No: {{student.rollno}}</p>
<p>Marks(Math): {{marks[3]}}</p>
</div>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.15/angular.min.js"></script>
</body>
</html>
Output
Open textAngularJS.html in your web browser. See the results as follows:
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
