Vue.js v-if、v-else-if与v-else指令详解及版本注意事项

代码示例展示

<!DOCTYPE html>
<html>
 <head>
 <meta charset="UTF-8">
 <title></title>
 <script src="../vue.js"></script>
 </head>
 <body>
 
 <div id="box">
 
 <!--实例1 vue 2.1.0以上版本支持 v-if v-else-if -->
 <div v-if="type === 'A'">
  A
 </div>
 <div v-else-if="type === 'B'">
  B
 </div>
 <div v-else-if="type === 'C'">
  C
 </div>
 <div v-else>
  Not A/B/C
 </div>
 <hr />
 
 <!--实例2 v-if / v-else-->
 <div v-if="type==='A'">ok!!!</div>
 <div v-else>no!!!</div>
 <hr />
 
 <!--实例3 模板中使用v-if / v-else-->
 <my-form :login-type="loginType"></my-form>
 <button @click="toggleFun">toggle loginType</button>
 
 
 </div>
 
 <script>
 
 var MyForm = {
 //template:"#myForm"
 props:['loginType'],
 template:`
  <div v-if="loginType === 'username'">
  <label>Username</label>
  <input placeholder="Enter your username" key="username-input"/>
  </div>
  <div v-else>
  <label>Email</label>
  <input placeholder="Enter your email address" key="email-input"/>
  </div>
 `
 }
 
 var app = new Vue({
 el:'#box',// ().$mount("#box");
 data:{
  type:'C',
  loginType:'username'
 },
 components:{
  "my-form":MyForm
 },
 methods:{
  toggleFun: function() {
  this.loginType = this.loginType === 'username'? 'email':'username';
  }
 },
 created:function (){
 }
 });
 </script>
 </body>
</html>