如何在JavaScript中将单键数组映射到多嵌套值数组

我刚学JavaScript一个月，现在需要把arr1里的键分配给arr2中每个嵌套数组的对应字符串，生成对象数组。

给定数据 #

const arr1 = ["Date","Start","High","Low","End","AdjEnd","Amount"] // 要分配的键
const arr2 = [["1997-06-01","75","80","65","78","79","3000"],
         ["1997-06-02","70","75","60","73","74","3300"],
         ["1997-06-03","80","85","70","83","84","3800"],...] // 包含1万+条此类嵌套数组

期望输出 #

const newArray = [
{
  Date: "1997-06-01",
  Start: "75",
  High: "80",
  Low: "65",
  End: "78",
  AdjEnd: "79",
  Amount: "3000"
},
{
  Date: "1997-06-02",
  Start: "70",
  High: "75",
  Low: "60",
  End: "73",
  AdjEnd: "74",
  Amount: "3300"
},
{
  Date: "1997-06-03",
  Start: "80",
  High: "85",
  Low: "70",
  End: "83",
  AdjEnd: "84",
  Amount: "3800"
}
// 后续所有嵌套数组对应生成的对象
]

当前低效实现 #

我能写出下面的代码得到正确格式，但这种手动逐个处理的方式对上万条数据完全不实用：

var result1 = {};
arr1.forEach((key, i) => result1[key] = arr2[0][i]);

var result2 = {};
arr1.forEach((key, i) => result2[key] = arr2[1][i]);

// 还要继续写result3、result4...

var allresult = [result1, result2] // 还要手动添加所有result
console.log(allresult);

高效解决方案 #

方法1：map + reduce 组合 #

遍历arr2的每个嵌套数组，用reduce将键与对应值绑定生成对象：

const newArray = arr2.map(item => {
  return arr1.reduce((obj, key, index) => {
    obj[key] = item[index];
    return obj;
  }, {});
});

方法2：map + forEach（更直观） #

如果对reduce逻辑不熟悉，用forEach构建对象的写法更易懂：

const newArray = arr2.map(item => {
  const obj = {};
  arr1.forEach((key, index) => {
    obj[key] = item[index];
  });
  return obj;
});

方法3：Object.fromEntries（ES2019+） #

将键数组与每个嵌套数组配对成键值对数组，再直接转换为对象，代码更简洁：

const newArray = arr2.map(item => {
  const entries = arr1.map((key, index) => [key, item[index]]);
  return Object.fromEntries(entries);
});

以上三种方法都能高效处理上万条数据，无需手动逐个创建对象，完全自动化完成键值映射。

内容的提问来源于stack exchange，提问作者pl9nt