比较两个数组并将状态放入另一个数组（如果存在与否）答案

【问题标题】：compare two array and put a status in an other array if it exist or not比较两个数组并将状态放入另一个数组（如果存在与否）
【发布时间】：2022-06-15 22:09:04
【问题描述】：

所以我有一个包含所有玩家的数组，一个只包含一个被选中的数组，如果他被选中，我想要另一个数组的状态。我尝试将元素与状态进行比较和推送，但没有达到我想要的。

这是数组

  const all = [
    {
      playerId: '294',
      firstName: 'MMM',
    },
    {
      playerId: '295',
      firstName: 'arkiv',
    },
    {
      playerId: '296',
      firstName: 'julio',
    },
    {
      playerId: '297',
      firstName: 'sss',
    },
  ];

const selected = [
    {
      playerId: '296',
      firstName: 'julio',
    },
    {
      playerId: '297',
      firstName: 'sss',
    },
  ];

这就是我想要达到的目标

  const res = [
    { playerId: '294', firstName: 'MMM', status: false },
    { playerId: '295', firstName: 'arkiv', status: false },
    { playerId: '296', firstName: 'julio', status: true },
    { playerId: '297', firstName: 'sss', status: true },
  ];

我在这里设置了一个工作环境：https://stackblitz.com/edit/react-lkcqcd?file=src%2FApp.js

感谢关注！

【问题讨论】：

标签： javascript arrays json

【解决方案1】：

您可以使用Array#some 来检查玩家的id 是否在选定的数组中。

const all=[{playerId:'294',firstName:'MMM',},{playerId:'295',firstName:'arkiv',},{playerId:'296',firstName:'julio',},{playerId:'297',firstName:'sss',},],selected=[{playerId:'296',firstName:'julio',},{playerId:'297',firstName:'sss',},];
all.forEach(player => player.status = 
              selected.some(x => x.playerId === player.playerId));
console.log(all);

【讨论】：

【解决方案2】：

您可以创建选定玩家的Set，并使用此集合添加status 字段。

const 
  all = [
    { playerId: "294", firstName: "MMM" },
    { playerId: "295", firstName: "arkiv" },
    { playerId: "296", firstName: "julio" },
    { playerId: "297", firstName: "sss" },
  ],
  selected = [
    { playerId: "296", firstName: "julio" },
    { playerId: "297", firstName: "sss" },
  ],
  selectedSet = new Set(selected.map((player) => player.playerId)),
  res = all.map((player) => ({
    ...player,
    status: selectedSet.has(player.playerId),
  }));

console.log(res);

【讨论】：