php - 将嵌套数组编码为没有数组索引的正确 json

Question

我有一个示例 2d $tasks 数组，它描述了一个嵌套结构:

Array
(
    [14] => Array
        (
            [Id] => 14
            [parentId] => null
            [Name] => T1
        )

    [40] => Array
        (
            [Id] => 40
            [parentId] => null
            [Name] => T5
        )

    [41] => Array
        (
            [Id] => 41
            [parentId] => null
            [Name] => T4
        )

    [22] => Array
        (
            [Id] => 22
            [parentId] => 14
            [Name] => T2
        )

    [43] => Array
        (
            [Id] => 43
            [parentId] => 22
            [Name] => T2 child
        )

    [42] => Array
        (
            [Id] => 42
            [parentId] => 14
            [Name] => T3
        )

)

我使用下面的代码将其转换为适当的树结构:

$sortedArray = array();
// get first level
foreach($tasks as $k => $v){
    if($v['parentId'] == 'null'){
        $sortedArray[$k] = $v;
        unset($tasks[$k]);
    }
}
// sort parents
asort($sortedArray);

function getChildren(array & $a1, array & $a2){
    foreach($a1 as $k => $v){
        findChildren($v, $a2, $k);      
    }
}

function findChildren($rec1, array & $a2, $key){

    foreach($a2 as $k => $v){
        if($rec1['parentId'] == $v['Id']){
            $a2[$k]['children'][$rec1['Id']] = $rec1;
            unset($tasks[$key]);
        } else {
            if (isset($v['children'])){
                findChildren($rec1, $a2[$k]['children'], $key);
            }
        }
    }
}

findChildren($tasks, $sortedArray);

运行此代码后输出 $sortedArray 如下所示:

Array
(
    [14] => Array
        (
            [Id] => 14
            [parentId] => null
            [Name] => T1
            [children] => Array
                (
                    [22] => Array
                        (
                            [Id] => 22
                            [parentId] => 14
                            [Name] => T2
                            [children] => Array
                                (
                                    [43] => Array
                                        (
                                            [Id] => 43
                                            [parentId] => 22
                                            [Name] => T2 child
                                        )

                                )

                        )

                    [42] => Array
                        (
                            [Id] => 42
                            [parentId] => 14
                            [Name] => T3
                        )

                )

        )

    [40] => Array
        (
            [Id] => 40
            [parentId] => null
            [Name] => T5
        )

    [41] => Array
        (
            [Id] => 41
            [parentId] => null
            [Name] => T4
        )

)

问题是，在当前状态下对该输出数组调用 json_encode 之后，我得到:

{"14":{"Id":"14","parentId":"null"...

所以所有嵌套数组都插入了它们的索引。我知道我可以使用 array_values 修复第一层。但是是否有任何简单的方法可以对所有级别执行此操作？没有它，我最终得到的“ child ”不是数组而是对象，这让我不满意。

Answer 1

您的帖子中没有代码，但是 $tasks 是作为关联数组创建的。在您的示例中，您还像关联数组一样遍历 $tasks:

foreach($tasks as $k => $v){
    ...
}

您需要像使用数字数组一样将子项添加到 $tasks；区别在于:

//associative array
$test = array();
$test["43"] = "hello";
$test["40"] = "hello1";
$test["23"] = "hello2";
print_r($test);

//numeric array
$testb = array(); 
$testb[] = "hello";
$testb[] = "hello1";
$testb[] = "hello2";
print_r($testb);

实例:http://codepad.org/tsOhX88h

对于数字数组，您引用的顶级索引(例如 14)是问题 {"14":{"Id":"14","parentId":"null".. . 不再存在。

作为简单的最后一步，使用此代码将关联数组中的项目推送到新的数值数组:

$finalArray = array();
foreach ($sortedArray as $key=>$val ){
    $finalArray[] = $sortedArray[$key];
}
print_r($finalArray);

实例:http://codepad.org/uSGSr1DC

或者您可以使用 array_values 一次性完成:

$finalArray = array();
$finalArray = array_values($sortedArray);
print_r($finalArray);

实例:http://codepad.org/D7uBSRr8