preg_replace

Perform a regular expression search and replace.

preg_replace Function synopsis

preg_replace(
    array|string $pattern,
    array|string $replacement,
    array|string $subject,
    int $limit = -1,
    &$count = null
  ): array|string|null

Parameters

$pattern

Typearray|string

The pattern to search for. It can be either a string or an array with strings.

$replacement

Typearray|string

The string or an array with strings to replace. If this parameter is a string and the $pattern parameter is an array, all patterns will be replaced by that string. If both $pattern and $replacement parameters are arrays, each $pattern will be replaced by the $replacement counterpart. If there are fewer elements in the $replacement array than in the $pattern array, any extra $patterns will be replaced by an empty string.

$subject

Typearray|string

The string or an array with strings to search and replace.

$limit

OptionalTypeintDefault value-1

The maximum possible replacements for each pattern in each $subject string. Defaults to -1 (no limit).

$count

Passed by reference, OptionalDefault valuenull

If specified, this variable will be filled with the number of replacements done.

Note that the parameter $count is passed by reference, and contains additional/updated context data that may be useful.

Return value

Typearray|string|null

preg_replace returns an array if the $subject parameter is an array, or a string otherwise.

If matches are found, the new $subject will be returned, otherwise $subject will be returned unchanged or null if an error occurred.