用方括号代替逗号使用foreach用PHP创建JSON

$data = [
    'name' => 'John Doe',
    'age' => 30,
    'email' => 'john.doe@example.com',
    'hobbies' => ['reading', 'traveling', 'sports']
];

$json = '{';
$first = true;

foreach ($data as $key => $value) {
    if (!$first) {
        $json .= ',';
    }
    $first = false;
    $json .= '"' . $key . '":';
    
    if (is_array($value)) {
        $json .= '[';
        $i = 0;
        foreach ($value as $item) {
            if ($i > 0) {
                $json .= ',';
            }
            $json .= '"' . $item . '"';
            $i++;
        }
        $json .= ']';
    } else {
        $json .= '"' . $value . '"';
    }
}

$json .= '}';
echo $json;