preg_grep_with_error

Note

This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information.

preg_grep, but populates $error in case of error

function preg_grep_with_error(
  string $pattern,
  varray_or_darray<mixed> $input,
  inout ?int $error,
  int $flags = 0,
): mixed;

If the function runs normally with no errors, then $error is set to null. Otherwise, if an error occurs, $error is set to an error code constant from the list defined in builtins_preg.hhi.

Parameters

• string $pattern
• varray_or_darray<mixed> $input
• inout ?int $error
• int $flags = 0

Returns

• mixed