如何拆分含嵌套数组的二维数组，生成多个单值关联数组？

问题描述 #

POST请求接收的数据：

[{"master":"80216","assign":["80491","80514","80575"]}]

需要转换为以下格式，将嵌套的assign数组拆分为多个单值对象：

[{"master":"80216","assign":"80491"}]
[{"master":"80216","assign":"80514"}]
[{"master":"80216","assign":"80575"}]

JavaScript 实现 #

使用flatMap和map组合展开嵌套数组：

// 解析POST接收的JSON数据
const input = JSON.parse('[{"master":"80216","assign":["80491","80514","80575"]}]');

// 拆分嵌套数组生成目标结构
const result = input.flatMap(item => 
  item.assign.map(assignVal => ({ master: item.master, assign: assignVal }))
);

// 按要求格式逐行输出
result.forEach(obj => console.log(JSON.stringify([obj])));

PHP 实现 #

通过双层循环拆分嵌套数组：

// 解析POST接收的JSON数据
$input = json_decode('[{"master":"80216","assign":["80491","80514","80575"]}]', true);

$result = [];
foreach ($input as $item) {
    // 遍历assign数组生成单值对象
    foreach ($item['assign'] as $assignVal) {
        $result[] = [
            'master' => $item['master'],
            'assign' => $assignVal
        ];
    }
}

// 逐行输出目标格式
foreach ($result as $obj) {
    echo json_encode([$obj]) . PHP_EOL;
}

Python 实现 #

通过循环拆分嵌套结构：

import json

# 解析POST接收的JSON字符串
input_data = json.loads('[{"master":"80216","assign":["80491","80514","80575"]}]')

result = []
for item in input_data:
    master_id = item['master']
    for assign_id in item['assign']:
        result.append({'master': master_id, 'assign': assign_id})

# 按要求格式输出
for obj in result:
    print(json.dumps([obj]))

内容的提问来源于stack exchange，提问作者user1738638