Edit in JSFiddle

Vue.component('click-count', {
	data: function() {
  	return {
    	count: 0
    }
  },
  template: `
  	<button @click="plus">
      我被按了 {{ count }} 下
    </button>
  	</button-counter>
  `,
  methods: {
  	plus: function() {
    	this.count+=1
    }
  }
})


let vm = new Vue({
	el: '#app',
  /* data: {
    count: 0
  },
  methods: {
    plus: function() {
      this.count++
    }
  } */
})

<div id="app">
  <!-- <button-counter>
    <button @click="plus">
      我被按了 {{ count }} 下
    </button>
  </button-counter> -->
  <click-count></click-count>
  <click-count></click-count>
  <click-count></click-count>
  <click-count></click-count>
  <click-count></click-count>
</div>