The very first Vue.js example

HTML

<script src="http://vuejs.org/js/vue.min.js"></script>
<div id="demo">
    <button @click="open">Click me!
    </button>

    <button @click="open">Click me!
    </button>

    <button @click="open">Click me!
    </button>

    <button @click="open">Click me!
    </button>

</div>

JavaScript

var demo = new Vue({
    el: '#demo',
    methods: {
    	open: function(event) {
        event.target.innerHTML = "Hello!";
      	console.log(event.target);
      }
    }
})