4. computed

HTML

<div id="app">
    <div v-text="usernameResolver">
    
    </div>
    <button @click="change">click
    
    </button>
</div>

Vue

new Vue({
	el: '#app',
  data: {
    count: 0,
    username: '',
    newValue: '',
  },
  methods: {
  	change: function() {
    	this.username;
    },
    math: function() {
    	return Math.random();
    }
  },
  computed: {
  	getCount() {
    	return this.count + '개';
    },
    usernameResolver: {
    	get() {
      	return this.username + this.math();
      },
      set(newValue) {
      	this.username = newValue;
        this.newValue = newValue + '♡';
      },
    }
  }
});