<template>
  <div>
    <div><input type="checkbox" v-model="checkAll" />全选</div>
    <div><input type="checkbox" @change="inverse" />反选</div>
    <div class="fruit" v-for="(item, index) in fruits" :key="index">
      <input type="checkbox" v-model="model" :value="item.value"/>
      {{ item.label }}
    </div>
    <div>已选择:{{ model }} 总价:{{total}}</div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      fruits: [
        {
          label: "Apple",
          value: "apple",
          price: 2.5,
        },
        {
          label: "Banana",
          value: "banana",
          price: 3,
        },
        {
          label: "Cherry",
          value: "cherry",
          price: 5,
        },
        {
          label: "Orange",
          value: "orange",
          price: 1.5,
        },
      ],
      model: [],
    };
  },
  methods: {
    inverse() {
      this.fruits.forEach(fruit=>{
        let index = this.model.findIndex((item) => item === fruit.value);
        if (index > -1) {
          this.model.splice(index, 1);
        } else {
          this.model.push(fruit.value);
        }
      })
    },
  },
  computed: {
    checkAll:{
      get(){
        this.model.length === this.fruits.length
      },
      set(val){
        console.log(val)
        if(val){
          this.model=[]
          this.fruits.forEach(item=>{
            this.model.push(item.value)
          })
        }else{
          this.model=[]
        }
      }
    },
   total() {
      let t = 0;
      this.model.forEach((item) => {
        let index = this.fruits.findIndex((fruit) => fruit.value === item);
        t += this.fruits[index].price;
      });
      return t;
    },
  },
};
</script>

<style lang="scss" scoped>
</style>