Vue

by hysunny

HTML

<div id="app">
     <p>$data.$test： {{ $data.$test }}</p>
     <p>isChange: {{ isChange }}</p>
     <button @click="add">add</button>
</div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#app {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  transition: all 0.2s;
}

li {
  margin: 8px 0;
}

h2 {
  font-weight: bold;
  margin-bottom: 15px;
}

del {
  color: rgba(0, 0, 0, 0.3);
}

Vue

new Vue({
  el: "#app",
  data: {
    $test: 1,
    isChange: false
  },
  methods: {
  	add() {
        this.$data.$test++
    }
  },
  watch: {
  	'$data.$test'(val, oldVal) {
    	this.isChange = !this.isChange
    }
  }
})