<div id="app">
<div class="box" :class="{'yellow': change}"></div>
<button class="changeColor btn btn-primary" @click="change = !change">Change Color</button>
</div>.box {
width: 250px;
height: 250px;
background-color: blue;
}
.box.yellow {
background-color: yellow;
}
var app = new Vue({
el: "#app",
data: {
change: false
}
});
