<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
    </head>
    <body>
        <div id="app">
            <div>{{msg}}</div>
            <button @click="lang">浪起来</button>
            <button @click="stop">别浪</button>

        </div>
    </body>
    <script src="vue.js"></script>
    <script>
        var vm=new Vue({
            el:'#app',
            data:{
                msg:'猥琐发育,别浪~~~~',
                intervalId:null
            },
            methods:{
                lang() {
                    if(this.intervalId!=null) return;
                    this.intervalId=setInterval( () =>{
                        var start = this.msg.substring(0,1);
                        var end= this.msg.substring(1);
                        this.msg=end+start;
                    },400)
                    
                },stop(){
                    clearInterval(this.intervalId)
                    this.intervalId=null;
                }
            }})
    </script>

</html>