小编Hma*_*man的帖子

我有数组selectedItems，当我尝试更新现有对象时：

i.e. [{lable: "one", uniqueId: 1}, {lable: "two", uniqueId: 1}] 

至：

i.e. [{lable: "one", uniqueId: 1}, {lable: "two", uniqueId: 3}]

它将整个数组替换为：

 [ { lable: "two", uniqueId: 3 }]

我该如何避免呢？

handleChange = (label, uniqueId) => {
  const { selectedItems } = this.state
  const findExistingItem = selectedItems.find((item) => {
    return item.uniqueId === uniqueId;
  })

  if(findExistingItem) {
    selectedItems.splice(findExistingItem);
    this.setState(state => ({
      selectedItems: [...state.selectedItems, {
        label, uniqueId
      }]
    }))
  } else {
    this.setState(state => ({
      selectedItems: [...state.selectedItems, {
        label, uniqueId
      }]
    })) …