Vue监听使用方法和过滤器实现

      Vue.component('myLi',{
			template:`
			`
		});
               var App={
			data(){
				return{
					price:0,
					msg:'hello filter'
				}
			},
			template:`
			<div>
			 <input type='number' v-model='price'  />
			 <h3>{{price | myCurrentcy}}</h3>
			 <h4>{{msg |myReverse 	 }}</h4>
			</div>
			`,
			filters:{
				//  声明过滤器
				myCurrentcy:function(value){
					return "￥"+value
				}
			}
		};
		
		new Vue({
			el:'#app',
			components:{
				App,
			},
			template:`<App/>`
		})            

    Vue.filter('myReverse',function(value){
			return value.split('').reverse().join('');
			
		});`

  <input type="text"  v-model="msg">
  	<h3>{{msg}}</h3>
  new Vue({
  		el:'#app',
  		data(){
  			return{
  			msg:'',
  			stus:[{name:'jack'}]
  			}
  		},
  		watch:{
  			msg:function(newV,oldV){
  				console.log(newV,oldV);
  				if(newV ==='sir'){
  					console.log('sir来了')
  				}
  			}  

	<button @click="stus[0].name='rose'">改变 </button>
			<h4>{{stus[0].name}}</h4>
  new Vue({
				el:'#app',
				data(){
					return{
					msg:'',
					stus:[{name:'jack'}]
					}
				},
	
					 // 监听复杂数据类型 object array 深度监听	
					stus:{
						deep:true,//深度监听
						handler:function(newV,oldV){
							console.log(newV[0].name);
						}
					}
				}