<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>vue</title>
<script src="vue.js"></script>
</head>
<body>
<!-- vue中的计算属性和侦听器
计算属性：
computed:{}
性能高，当依赖的数据没有发生变化时，不会重新加载
侦听器：
watch
-->
<div id="root">
姓：<input v-model="firstname" />
名：<input v-model="lastname" />
<div>{{fullName}}</div>
<div>{{count}}</div>
</div>
<script>
new Vue({
el:"#root",
data:{
firstname:'',
lastname:'',
count: 0
},
computed:{
fullName: function() {
return this.firstname + ' ' + this.lastname
}
},
watch: {
firstname: function() {
this.count ++
},
lastname: function() {
this.count ++
},
fullName: function() {
this.count ++
}
}
})
</script>
</body>
</html>