vue 怎样点击加号让减号显示出来

Question

        const app = new Vue({
            el:'#app',
            data:{
                counter:1,
                show:true
            },
            methods: {
                add:function(){
                    this.counter++
                },
                sub:function(){
                    if(this.counter>0){
                        this.counter--
                    }else{
                        this.counter = 0
                        this.show = !this.show

                    }
                }
            }
        })

    <div id="app">
  
        <div>
            
            <button v-on:click="add">+</button>
            <span>{{counter}}</span>
            <button @click="sub" v-show="show">-</button>
        </div>
    </div>

Answer 1

哈哈，自己解答了