new Vue({
el: "#app",
data: {
name: 'www'
},
methods: {
idname: function(event) {
this.name = event.target.value;
}
}
})
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js">
</script>
<div id='app'>
<input type="text" v-on:input="idname">
<h1>
{{name}}
</h1>
</div>