AngularJS introductory tutorial - AngularJS expression_AngularJS

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.

AngularJS expression format: {{expression }}

AngularJS expressions can be strings, numbers, operators and variables

Number operations {{1 + 5}}

String concatenation {{ 'abc' + 'bcd' }}

Variable operations {{ firstName + " " + lastName }}, {{ quantity * cost }}

Object {{ person.lastName }}

Array{{ points[2] }}

AngularJS Example

1.Angularjs numbers

<div ng-app="" ng-init="quantity=2;cost=5">
<p>总价： {{ quantity * cost }}</p>
</div> 

Output of the above example:

Total price: 10

Code comments:

ng-init="quantity=2;cost=5" //Equivalent to var quantity=2,cost=5;
in javascript The same functionality can be achieved using ng-bind

<div ng-app="" ng-init="quantity=1;cost=5">
<p>总价： <span ng-bind="quantity * cost"></span></p>
//这里的ng-bind相当于指定了span的innerHTML
</div> 

2.Angularjs string

<div ng-app="" ng-init="firstName='John';lastName='Snow'">
<p>姓名： {{ firstName + " " + lastName }}</p>
</div> 

Output

Name: Jone Snow

3. AngularJS Object

<div ng-app="" ng-init="person={firstName:'John',lastName:'Snow'}">
<p>姓为 {{ person.lastName }}</p>
</div> 

Output

The last name is Snow

4.AngularJS Array

<div ng-app="" ng-init="points=[1,15,19,2,40]">
<p>第三个值为 {{ points[2] }}</p>
</div>

Output

The third value is 19

The above is the introduction to AngularJS expressions in the AngularJS introductory tutorial introduced by the editor. I hope it will be helpful to everyone!