Vue

by ChangJoo Park

HTML

<div id="app">
  <div>
    {{ numberA }} + {{ numberB }} = 
  </div>
  <div>
      {{ sum }}
  </div>
  <button @click="numberA++">A++</button>
  <button @click="numberB++">B++</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: {
  	numberA: 1,
    numberB: 2
  },
  computed: {
  	sum () {
	     return this.numberA + this.numberB
    }
  },
  watch: {
  	sum(next, prev) {
    	if (next == 6) {
      window.alert('합이 6입니다.')
      }
    }
  }
})