preg_match_all

Perform a global regular expression match.

preg_match_all Function synopsis

preg_match_all(
    string $pattern,
    string $subject,
    &$matches = null,
    int $flags = 0,
    int $offset = 0
  ): int|false

Parameters

$pattern

Typestring

The pattern to search for, as a string.

$subject

Typestring

The input string.

$matches

Passed by reference, OptionalDefault valuenull

Array of all matches in multi-dimensional array ordered according to $flags.

$flags

OptionalTypeintDefault value0

Can be a combination of the following flags (note that it doesn't make sense to use PREG_PATTERN_ORDER together with PREG_SET_ORDER):

$flags accepts one or a bitmask of the following constant values:

• PREG_PATTERN_ORDER
• PREG_SET_ORDER
• PREG_OFFSET_CAPTURE
• PREG_UNMATCHED_AS_NULL

$offset

OptionalTypeintDefault value0

Normally, the search starts from the beginning of the subject string. The optional parameter $offset can be used to specify the alternate place from which to start the search (in bytes).

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

Return value

Typeint|false

Returns the number of full pattern matches (which might be zero), or false on failure.