AngularJS forms and controls can validate entered data.

AngularJS input validation syntax

AngularJS forms and controls can provide validation functions and warn users of illegal data entered.

AngularJS input validation example

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="https://cdn.bootcss.com/angular.js/1.4.6/angular.min.js"></script>
</head>
<body>

<h2>驗(yàn)證實(shí)例</h2>

<form ng-app="myApp" ng-controller="validateCtrl" 
name="myForm" novalidate>

<p>用戶名:<br>
<input type="text" name="user" ng-model="user" required>
<span style="color:red" ng-show="myForm.user.$dirty && myForm.user.$invalid">
<span ng-show="myForm.user.$error.required">用戶名是必須的。</span>
</span>
</p>

<p>郵箱:<br>
<input type="email" name="email" ng-model="email" required>
<span style="color:red" ng-show="myForm.email.$dirty && myForm.email.$invalid">
<span ng-show="myForm.email.$error.required">郵箱是必須的。</span>
<span ng-show="myForm.email.$error.email">非法的郵箱地址。</span>
</span>
</p>

<p>
<input type="submit"
ng-disabled="myForm.user.$dirty && myForm.user.$invalid ||  
myForm.email.$dirty && myForm.email.$invalid">
</p>

</form>

<script>
var app = angular.module('myApp', []);
app.controller('validateCtrl', function($scope) {
    $scope.user = 'John Doe';
    $scope.email = 'john.doe@gmail.com';
});
</script>

</body>
</html>

Run instance ?

Click the "Run instance" button to view the online instance