如何在PHP中遍历JSON对象的值？

$jsonString = '{"name":"John", "age":30, "city":"New York"}';
$data = json_decode($jsonString);

foreach ($data as $key => $value) {
    echo "Key: " . $key . ", Value: " . $value . "<br>";
}

function traverseJson($data) {
    foreach ($data as $key => $value) {
        if (is_array($value) || is_object($value)) {
            traverseJson($value); // 递归遍历子对象或数组
        } else {
            echo "Key: " . $key . ", Value: " . $value . "<br>";
        }
    }
}

traverseJson($data);