<ul class="top_bar">
<li class="top_cell"
v-for="cell in 5"
:class="{ 'active': cell === selected }"
@click="choose(cell)">
{{cell}}
</li>
</ul>
new Vue({
el:'.top_bar',
data:{
selected: null
},
methods:{
choose:function (index) {
this.selected = index
}
}
});