Edit in JSFiddle

var alertclickexample = new Vue({
  el: '#alert-click-example',
  data: {
  	name: 'Rehan'
  },
  methods: {

    showAlert: function(value) {
      alert('Oooh hi ' + value + '!')
    }

  }
})
<div id="alert-click-example">
  <button id="alert-button" v-on:click="showAlert(name)">Display Alert</button>
</div>