请尝试下面的解决方案

$json = '[{
        "id": "17",
        "pf_label": "Gender"
    },
    {
        "id": "18",
        "pf_label": "Age"
    },
    {
        "id": "12",
        "pf_label": "Address Line"
    }
]';

$jsondec = json_decode($json,true);
foreach ($jsondec as $key => $value) {
  $newjson[$value['id']] = $value['pf_label'];
}

$json2 = '[{
    "": "",
    "17": "male",
    "18": "27"
}, {
    "": "",
    "17": "female",
    "18": "26",
    "12": "japan"
}]';

$jsondec2 = json_decode($json2,true);
foreach ($jsondec2 as $key => $value) {
    foreach ($value as $key => $value) {      
      $newary[$newjson[$key]] = $value;           
    }
    $finalary[] = $newary;
}

$result = json_encode($finalary);

希望这对你有帮助！

你可以试试这个！

<?php
$jsonString1 = '[{
        "id": "17",
        "pf_label": "Gender"
    },
    {
        "id": "18",
        "pf_label": "Age"
    },
    {
        "id": "12",
        "pf_label": "Address Line"
    }
]';

$jsonString2 = '[{
    "": "",
    "17": "male",
    "18": "27"
}, {
    "": "",
    "17": "female",
    "18": "26",
    "12": "japan"
}]';

$array1 = json_decode($jsonString1, true);
$indexes = array();
foreach ($array1 as $element) {
    $indexes[$element['id']] = $element['pf_label'];
}

$array2 = json_decode($jsonString2, true);
foreach ($array2 as $element) {
    foreach ($element as $key => $value) {
        if ($key) {
            $singleElement[$indexes[$key]] = $value;
        } else {
            $singleElement[""] = "";
        }
    }
    $result[] = $singleElement;
}

var_dump($result);

演示