比較兩個陣列并將狀態放入另一個陣列（如果存在與否）

所以我有一個包含所有玩家的陣列，一個只有一個被選中的陣列，如果他被選中，我想要另一個陣列的狀態。我嘗試將元素與狀態進行比較和推送，但沒有達到我想要的。

這是陣列

  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',
    },
  ];

這就是我想要實作的

  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 },
  ];

我設定了一個在這里作業的環境：https ://stackblitz.com/edit/react-lkcqcd?file=src/App.js

感謝關注！

uj5u.com熱心網友回復：

您可以使用Array#some來檢查玩家的 id 是否在選定的陣列中。

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);

uj5u.com熱心網友回復：

您可以創建一組選定的玩家，并使用該組添加該status欄位。

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);

您也可以使用Array.prototype.find而不是創建一個集合，但這不是最佳選擇，除非selected陣列的大小非常小。

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" }],
  res = all.map((player) => ({
    ...player,
    status: !!selected.find((selPlayer) => selPlayer.playerId === player.playerId),
  }));

console.log(res);

uj5u.com熱心網友回復：

您可以在以下演示中使用Array#mapand ：Array#includes

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', }, ],

      output = all.map(
          player => 
          ({
              ...player,
              status:selected.map(({playerId}) => playerId)
              .includes(player.playerId)
          })
      );

console.log( output );

標籤：javascript 数组 json

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