过滤器的作用是格式化数据．

过滤器包含:

currency

date

filter

json

limitTo

lowercase

number

orderby

uppercase

使用方法：

1. 在表达式中添加过滤器

<div ng-app="myApp" ng-controller="personCtrl">

<p>The name is {{ lastName | uppercase }}</p>

</div>

<script>
angular.module('myApp',[]).controller('personCtrl',function($scope) {
    $scope.firstName = "John",$scope.lastName = "Doe"
});
</script>

<div ng-app="myApp" ng-controller="namesCtrl">

<p>Looping with objects:</p>
<ul>
  <li ng-repeat="x in names | orderBy:'name'">
    {{ x.name + ',' + x.country }}
  </li>
</ul>

</div>

<script>
angular.module('myApp',[]).controller('namesCtrl',function($scope) {
    $scope.names = [
        {name:'Jani',country:'Norway'},{name:'Carl',country:'Sweden'},{name:'Margareth',country:'England'},{name:'Hege',{name:'Joe',country:'Denmark'},{name:'Gustav',{name:'Birgit',{name:'Mary',{name:'Kai',country:'Norway'}
        ];
});
</script>

使用filter()函数

<div ng-app="myApp" ng-controller="myCtrl">
    <p>{{name|myFormat}}</p>
</div>
<script>
    var app = angular.module('myApp',[]);
    app.filter('myFormat',function() {
        return function(name) {
            var txt = "";
            for (var i = 0; i < name.length; i++) {
                txt += name[i].toUpperCase();
            }
            return txt;
        }
    });
    app.controller('myCtrl',function($scope) {
        $scope.name = "John";
    });
</script>