computed

当依赖的变量改变时，会重新计算结果。这种类型也是响应式的。

1
2
3
4
5
6
7
8
9
<div>
  part1:
  <input type="text" v-model="part1">
  <br>
  part2:
  <input type="text" v-model="part2">
  <br>
  part1+part2: {{part12}}
</div>
1
2
3
4
5
6
let part1 = ref()
let part2 = ref()

let part12 = computed(() => {
  return part1.value + part2.value;
})