如何在JavaScript中将对象数组转换为嵌套结构的单一对象

我有一个对象数组，需要将其合并为具备父子层级结构的单一对象。此前尝试过创建空对象并用for循环逐个添加内容，但因嵌套层级较多未成功；也用过lodash的_.flatten方法，同样没达到预期效果。

输入示例 #

let array = [
    {
        "Gender": "male",
        "Type": "backpacks",
        "Key": "size",
        "Values": "small,large,medium"
    },
    {
        "Gender": "male",
        "Type": "backpacks",
        "Key": "strap",
        "Values": "padded,non-padded"
    },
    {
        "Gender": "female",
        "Type": "backpacks",
        "Key": "pocket",
        "Values": "multiple,zip,buckle"
    },
    {
        "Gender": "female",
        "Type": "backpacks",
        "Key": "size",
        "Values": "small,large,medium"
    },
    {
        "Gender": "female",
        "Type": "sunglasses",
        "Key": "size",
        "Values": "XL,XXL,XXL"
    },
    {
        "Gender": "female",
        "Type": "sunglasses",
        "Key": "color",
        "Values": "red,black,yellow"
    }
]

期望输出 #

let obj = {
    "male": {
        "backpacks": {
            "size": "small,large,medium",
            "strap": "padded,non-padded"
        }
    },
    "female": {
        "backpacks": {
            "pocket": "multiple,zip,buckle",
            "size": "small,large,medium"
        },
        "sunglasses": {
            "size": "XL,XXL,XXL",
            "color": "red,black,yellow"
        }
    }
}

解决方案 #

原生JavaScript实现（使用Array.reduce） #

通过reduce遍历数组，逐步构建嵌套层级。每次迭代时检查当前层级的对象是否存在，不存在则创建空对象，最后赋值对应属性：

const result = array.reduce((acc, item) => {
    // 确保Gender层级存在
    if (!acc[item.Gender]) {
        acc[item.Gender] = {};
    }
    // 确保Type层级存在
    if (!acc[item.Gender][item.Type]) {
        acc[item.Gender][item.Type] = {};
    }
    // 赋值Key-Values
    acc[item.Gender][item.Type][item.Key] = item.Values;
    return acc;
}, {});

console.log(result);

Lodash实现（使用_.set） #

如果使用Lodash，不需要手动检查层级，_.set方法可以直接设置嵌套属性，不存在的层级会自动创建：

const _ = require('lodash');

const result = {};
array.forEach(item => {
    // 构建路径：[Gender, Type, Key]
    const path = [item.Gender, item.Type, item.Key];
    _.set(result, path, item.Values);
});

console.log(result);

这两种方法都能高效地将数组转换为目标嵌套结构，解决手动循环时层级判断繁琐的问题。

内容的提问来源于stack exchange，提问作者Subee Na