如何将 JSON 字符串转换为数组（PHP）？

使用下面的代码来解码json

$categories = json_decode($data);
$categories = $categories->data;

我从哪里得到这个

{"categories":[{"id":1,"name":"Utilities","apps":897,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/uti.jpg"},{"id":2,"name":"Productivity","apps":477,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/pro.jpg"},{"id":3,"name":"Music","apps":466,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/mus.jpg"},{"id":4,"name":"Travel","apps":289,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/tra.jpg"},{"id":5,"name":"Navigation","apps":297,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/nav.jpg"},{"id":6,"name":"Books","apps":271,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/boo.jpg"},{"id":7,"name":"Healthcare & Fitness","apps":250,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/hea.jpg"},{"id":8,"name":"Games","apps":5116,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/gam.jpg"},{"id":9,"name":"Social Networking","apps":272,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/soc.jpg"},{"id":10,"name":"Lifestyle","apps":434,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/lif.jpg"},{"id":11,"name":"Finance","apps":200,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/fin.jpg"},{"id":12,"name":"News","apps":128,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/new.jpg"},{"id":13,"name":"Photography","apps":481,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/pho.jpg"},{"id":14,"name":"Entertainment","apps":1251,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/ent.jpg"},{"id":15,"name":"Business","apps":221,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/bus.jpg"},{"id":16,"name":"Sports","apps":199,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/spo.jpg"},{"id":17,"name":"Education","apps":433,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/edu.jpg"},{"id":18,"name":"Medical","apps":262,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/med.jpg"},{"id":19,"name":"Weather","apps":64,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/wea.jpg"},{"id":20,"name":"Reference","apps":419,"iconurl":"http:\/\/static.apptrackr.org\/caticons\/ref.jpg"}]} 

我想转换成这样的数组

Array[0]
    {
       id => 1
       name => Utilities
       apps => 897
       iconurl => http:\/\/static.apptrackr.org\/caticons\/uti.jpg
    }

等等

这看起来像一个JSON 字符串。您可以使用json_解码()将其转换为 PHP 变量，例如

$obj = json_decode($json);
print_r($obj->categories); // array of StdClass objects

您可以定期访问和迭代类别数组

echo $obj->categories[0]->name; // Utilities
echo $obj->categories[1]->name; // Productivity
echo $obj->categories[2]->name; // Music

要将 StdClass 对象转换为数组，您可以这样做

$categories = array();
foreach (json_decode($json)->categories as $category) {
    $categories[] = (array) $category;
}
print_r($categories);

你也可以用拉姆达函数 and 数组映射:

// Before PHP5.3
$categories = array_map(
    create_function('$el', 'return (array) $el;'), 
    json_decode($json)->categories);

// After PHP5.3
$categories = array_map(
    function($el) { return (array) $el; }, 
    json_decode($json)->categories);