currentIndex

<ul>

<li v-for="(item,index) in movies" @click="changeColor(index)"

:class="{active:currentIndex===index}">

{{item}}---{{index}}

</li>

</ul>

el:'#app',

data:{

movies: ['七龙珠', '柯南', '你是我的荣耀'],

currentIndex: 0 ,

},

methods:{

changeColor(index){

this.currentIndex=index

}

}