vue_props div赋值props定义变量 templete获取

<div id="app">  
    <add v-bind:btn="h"></add>  
</div>  
<script>  
    var vm = new Vue({  
        el: '#app',  
        data: {  
            h: "hello"  
        },  
        components: {  
            "add": {  
                props: ['btn'],  
                template: "<button>btn：{{btn}}</button>",  
                data: function () {  
                    return {'btn': "123"};  //子组件同名的值被覆盖了  
                }  
            }  
        }  
    });  
</script>