JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://vuejs.org/js/vue.min.js"></script>

JavaScript

var vm = new Vue({
    data: {
        hoge: "foommm"
    }
});

vm.$watch("$data", function(val) {
    console.log("change: " + JSON.stringify(val));
});

vm.$data = {hoge: "bar"}; // change: {"hoge":"bar"} 

Vue.nextTick(function() {
    vm.$data.hoge = "baz"; // change: {"hoge":"baz"}
});