console 命令行工具 X clear

console

new Vue({
  el: "#app",
  data: {
    count: 0
  },
  methods: {
    sub: function() {
      this.count = this.count -1
    }
  }
})

<div id="app">
  <p v-bind="count<0 ? count++  : ''">
    {{count}}
  </p>
 <button v-on:click="count++">
    累加
  </button>
  <button v-on:click="sub">
    累减
  </button>
</div>