PHP将KB MB GB TB等转换为字节

function convertToBytes($size) {
    $unit = strtolower(substr($size, -2));
    $value = (int) $size;

    switch ($unit) {
        case 'kb':
            $value *= 1024;
            break;
        case 'mb':
            $value *= 1024 * 1024;
            break;
        case 'gb':
            $value *= 1024 * 1024 * 1024;
            break;
        case 'tb':
            $value *= 1024 * 1024 * 1024 * 1024;
            break;
    }

    return $value;
}

$bytes = convertToBytes('100 MB');
echo $bytes; // 输出：104857600