FFI::isNull (PHP 7 >= 7.4.0, PHP 8)FFI::isNull — Checks whether a FFI\CData is a null pointer 说明 public static FFI::isNull(FFI\CData &$ptr): bool Checks whether a FFI\CData is a null pointer. 参数 ptr The handle of the pointer to a C data structure. 返回值 Returns whether a FFI\CData is a null pointer.