Question

我有对象users的数组：

let state = {
  users: [
    {id: 1, name: 'Igor',  selected: false},
    {id: 2, name: 'Anton', selected: false},
    {id: 3, name: 'Vasya', selected: false},
    {id: 4, name: 'Pete',  selected: false},
    {id: 5, name: 'Dan',   selected: false}
  ], ....

一个适用于此对象的函数：

export function selectUser(userId) {
  if (state.users.find(item => item.id == userId).selected == false) {
    /* some code */

    //[needed] Code to update the user property selected to true

  } else {
    /* some other code */

    //[needed] Code to update the user property selected to true
  }
  emitChange();
}

如何做到这一点，不覆盖整个阵列，奇怪的是无法想到任何事情

Answer 1

find（）方法返回要更新的对象。因此，首先调用它并将其分配给变量，然后测试它是否存在，如果是，则使用它。

export function selectUser(userId) {
  var user = state.users.find(item => item.id == userId);

  if (user != 'undefined'){
    if (user.selected == false) {
      /* some code */

      user.name = 'New Name';
      // etc

    } else {
      /* some other code */
    }
  }

  emitChange();
}

Answer 2

根据真假案例中的评论，这应该有效：

attributes

Answer 3

如果你想切换属性，那么

export function selectUser(userId) {
  var user = state.users.find(user => user.id == userId);
  var isSelected = user.selected; 
  // state.users.forEach(user => user.selected = false ); deselect others 
  user.selected = !isSelected;
  emitChange();
}

更改对象数组中的一个值

3 个答案: