数组对象赋值和清空（不丢失响应式）

1.数组

ref

const array = ref([1,2,3]);

watch(array,()=>{
console.log(array.value);
},)

array.value = [];
array.value.length = 0

slice

const array = ref([1,2,3]);

watch(array,()=>{
console.log(array.value);
},)

array.value = array.value.slice(0,0);

reactive

const array = reactive([1,2,3]);

watch(()=>[...array],()=>{
  console.log(array);
},)

array.length = 0;

2.对象

cosnt obj = reactive({
  a:1
})

let ob = {
  a:2,
  c:3
}

Object.assign(obj,ob)