Find the JSFiddle here: https://jsfiddle.net/smax/q2s3fpku/

Or use this Code:

HTML:

<script src="https://npmcdn.com/vue/dist/vue.js"></script>
<div id="exercise">
    <!-- 1) Show an alert when the Button gets clicked -->
    <div>
        <button v-on:click="alertMe">Show Alert</button>
    </div>
    <!-- 2) Listen to the "keydown" event and store the value in a data property (hint: event.target.value gives you the value) -->
    <div>
        <input type="text" v-on:keydown="value = $event.target.value">
        <p>{‌{ value }}</p>
    </div>
    <!-- 3) Adjust the example from 2) to only fire if the "key down" is the ENTER key -->
    <div>
        <input type="text" v-on:keydown.enter="value = $event.target.value">
        <p>{‌{ value }}</p>
    </div>
</div>


CSS:

None

JavaScript:

new Vue({
        el: '#exercise',
        data: {
            value: ''
        },
        methods: {
        alertMe: function() {
          alert('Alert!');
          }
        }
    });