PHP教程：在JSON数组的每个对象中高效嵌入静态数据

[
    {
        "user_id": "1",
        "name": "test 1"
    },
    {
        "user_id": "2",
        "name": "test 2"
    }
]

$staticData = array(
    "student_list" => array(
        array("stu_id" => 1, "name" => "abc"),
        array("stu_id" => 2, "name" => "xyz")
    ),
    "class" => "12th",
    "average_score" => "5",
    "results" => array(
        array("result_date" => "2012-12-13", "city" => "city 1"),
        array("result_date" => "2015-10-13", "city" => "city 2")
    )
);

[
    {
        "user_id": "1",
        "name": "test 1",
        "student_list": [
            { "stu_id": 1, "name": "abc" },
            { "stu_id": 2, "name": "xyz" }
        ],
        "class": "12th",
        "average_score": "5",
        "results": [
            { "result_date": "2012-12-13", "city": "city 1" },
            { "result_date": "2015-10-13", "city": "city 2" }
        ]
    },
    // ... 其他用户对象
]

<?php

// 1. 模拟从数据库或API获取的原始JSON数据
// 实际应用中，$value 可能是 $this->TestModel->get_user_details($userIds); 的返回值
$value = '[
    {
        "user_id": "1",
        "name": "test 1"
    },
    {
        "user_id": "2",
        "name": "test 2"
    },
    {
        "user_id": "3",
        "name": "test 3"
    }
]';

// 2. 定义需要嵌入的静态数据结构
$staticData = array(
    "student_list" => array(
        array("stu_id" => 1, "name" => "abc"),
        array("stu_id" => 2, "name" => "xyz")
    ),
    "class" => "12th",
    "average_score" => "5",
    "results" => array(
        array("result_date" => "2012-12-13", "city" => "city 1"),
        array("result_date" => "2015-10-13", "city" => "city 2")
    )
);

// 3. 将JSON字符串解码为PHP关联数组
// json_decode的第二个参数为true，表示将JSON对象解码为关联数组而非对象
$decodedArray = json_decode($value, true);

// 4. 遍历主数组，并将静态数据合并到每个子元素中
if (is_array($decodedArray)) {
    foreach ($decodedArray as $key => $item) {
        // array_merge 函数用于合并两个或多个数组
        // 对于关联数组，如果键名相同，后面的数组会覆盖前面的数组的值
        // 在本例中，静态数据的键名与原始数据不冲突，因此会成功追加
        $decodedArray[$key] = array_merge($item, $staticData);
    }
}

// 5. 将修改后的PHP数组重新编码为JSON字符串
$finalJson = json_encode($decodedArray, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);

// 输出结果
echo $finalJson;

?>