javascript - 如何将数据从一个数组/对象推送到另一个数组/对象中？

Question

我正在构建的应用程序使用 XMLHttpRequest，并且我已将响应文本解析为一个名为 data3 的变量，该变量返回以下内容:

[]
0: {round_fk: "1", player_name: "John Doe", player_score: "-45"}
1: {round_fk: "1", player_name: "Mark Doe", player_score: "-7"}
2: {round_fk: "2", player_name: "Dave Doe", player_score: "-7"}
3: {round_fk: "2", player_name: "Chris Doe", player_score: "-7"}

我试图根据 round_fk 对这个对象数组进行排序，并将具有相同 round_fk 的所有回合放入另一个数组中，其中每个对象都有一个与 round_fk 相对应的键。它看起来像这样:

let sortRounds = [
    [
      1: round_fk: "1", player_name: "John Doe", player_score: "-45",
         round_fk: "1", player_name: "Mark Doe", player_score: "-7"
    ],
    [
      2: round_fk: "2", player_name: "Dave Doe", player_score: "-7",
         round_fk: "2", player_name: "Chris Doe", player_score: "-7"
    ]
];

到目前为止，这就是我所拥有的:

let sortRound = [];
          console.log(sortRound);
          for(i = 0; i < data3.length; i++){
            let roundFk = data3[i].round_fk;
            if(!(roundFk in sortRound)){
              sortRound[roundFk] = [];
            }
            Object.keys(sortRound).forEach(function(key){
              if(key == roundFk){
                key.push(data3[i]);
              }
            });
          }

我创建了一个包含与 round_fk 对应的键的数组，但是当我尝试将数据推送到这些新键时，我收到以下错误消息“Uncaught TypeError: key.push is not a function”。

我已将对象从常规对象更改为数组，push 函数现在不应该工作吗？我这里哪里出错了？我已经被困在这个问题上有一段时间了，非常感谢任何帮助!

谢谢!克里斯

Answer 1

有更好的方法可以做到这一点，但让我们从解决问题开始。

错误显示Uncaught TypeError: key.push is not a function。这是指这一行:

key.push(data3[i]);

这应该是

sortedRounds[key].push(data3[i]);

为什么？

您正在尝试 .push 到某个键。在数组(例如 sortRounds)中，键看起来像 [0,1,2]

所以你的代码相当于0.push(data3[i])。你不能推到0!它不是一个数组。

更好的解决方案

let sortRound = [];
for(i = 0; i < data3.length; i++){
  let roundFk = data3[i].round_fk;
  if(!(roundFk in sortRound)){
    sortRound[roundFk] = [];
  }

  // We already know the correct key here, 
  // so no need to loop through the array again
  sortRound[roundFk].push(data3[i]);
}