<html>
<body>
	<div id="app">
		<div v-if="parm.age >= 21">{{parm.age}}: Free Beer for You!</div>
		<div v-else>{{parm.age}}: No Beer for You!</div>

		<div v-if="parm.age + 5 >= 21">{{parm.age + 5}}: Free Beer for You!</div>
		<div v-else>{{parm.age + 5}}: No Beer for You!</div>
	</div>
</body>

<script src="vue.js"></script>
<script>
// ----------------------------------------------------------------
// v-if determines if tag will exist in DOM
var app = new Vue({
	el: '#app',
	data: {
		parm: {age:18}
	}
});
// ----------------------------------------------------------------
</script>

</html>

Add vue/feat/directives v-if and v-else
Add vue/feat/directives v-if and v-else
