AngularJS自定义Directive不一定返回对象

angular.module(‘modulename‘)
    .directive(‘myDirective‘, function(){
        return {
            restrict: ‘EA‘, //E表示element, A表示attribute,C表示class，M表示commnent,即注释
            scope:{
                title: ‘@‘ //@读属性值，=双向绑定，&用户函数
            }
            template: ‘<div>{{myVal}}</div>‘,
            templateUrl: ‘app/sample.html‘,
            controller: ‘myController‘,
            link:function($scope, element, attrs){}//DOM操作
        };
    })

var app=angular.module(‘superhero‘,[]);


app.directive("enter", function(){
   return function(scope, element){
       element.bind("mouseenter", function(){
           console.log(‘I am inside of you‘);
       })
   }
});

app.directive("leave", function(){
    return function(scope, element){
        element.bind("mouseleave", function(){
            console.log(‘i am leaving on a jet plane‘);
        })
    }
})

app.directive("enter", function(){
   return function(scope, element, attrs){
       element.bind("mouseenter", function(){
           element.addClass(attrs.enter);
       })
   }
});

app.directive("leave", function(){
    return function(scope, element,attrs){
        element.bind("mouseleave", function(){
            element.removeClass(attrs.enter);
        })
    }
})