An incredibly powerful alternative to other answers here:
ng-class="[ { key: resulting-class-expression }[ key-matching-expression ], .. ]"
Some examples:
1. Simply adds 'class1 class2 class3' to the div:
<div ng-class="[{true: 'class1'}[true], {true: 'class2 class3'}[true]]"></div>
2. Adds 'odd' or 'even' classes to div, depending on the $index:
<div ng-class="[{0:'even', 1:'odd'}[ $index % 2]]"></div>
3. Dynamically creates a class for each div based on $index
<div ng-class="[{true:'index'+$index}[true]]"></div>
If $index=5
this will result in:
<div class="index5"></div>
Here's a code sample you can run:
var app = angular.module('app', []);
app.controller('MyCtrl', function($scope){
$scope.items = 'abcdefg'.split('');
});
.odd { background-color: #eee; }
.even { background-color: #fff; }
.index5 {background-color: #0095ff; color: white; font-weight: bold; }
* { font-family: "Courier New", Courier, monospace; }
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.1/angular.min.js"></script>
<div ng-app="app" ng-controller="MyCtrl">
<div ng-repeat="item in items"
ng-class="[{true:'index'+$index}[true], {0:'even', 1:'odd'}[ $index % 2 ]]">
index {{$index}} = "{{item}}" ng-class="{{[{true:'index'+$index}[true], {0:'even', 1:'odd'}[ $index % 2 ]].join(' ')}}"
</div>
</div>