Regex Online Tester (preg_match_all)

preg_match_all ( string $pattern , string $subject [, array &$matches [, int $flags = PREG_PATTERN_ORDER [, int $offset = 0 ]]] ) : int

Searches subject for all matches to the regular expression given in pattern and puts them in matches in the order specified by flags. After the first match is found, the subsequent searches are continued on from end of the last match.

$pattern:

The pattern to search for, as a string.

$subject:

The input string.

$matches:

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

$flags:

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):

PREG_PATTERN_ORDER
Orders results so that $matches[0] is an array of full pattern matches, $matches[1] is an array of strings matched by the first parenthesized subpattern, and so on.
REG_SET_ORDER
Orders results so that $matches[0] is an array of first set of matches, $matches[1] is an array of second set of matches, and so on.
PREG_OFFSET_CAPTURE
If this flag is passed, for every occurring match the appendant string offset will also be returned. Note that this changes the value of matches into an array of arrays where every element is an array consisting of the matched string at offset 0 and its string offset into subject at offset 1.

offset

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).

Return Values

Returns the number of full pattern matches (which might be zero), or FALSE if an error occurred.

Function

$replace

$pattern

$subject

See some popular examples:

$pattern modificators

`[abc]`	A single character: a, b or c
`[^abc]`	Any single character except: a, b, or c
`[a-z]`	Any single character in the range a-z
`[a-zA-Z]`	Any single character in the range a-z or A-Z
`^`	Start of line
`$`	End of line
`\A`	Start of string
`\z`	End of string
`.`	Any single character
`\s`	Any whitespace
`\S`	Any non-whitespace character
`\d`	Any digit
`\D`	Any non-digit
`\w`	Any word character (letter, number, underscore)
`\W`	Any non-word character
`\b`	Any word boundary
`(...)`	Create a capture group
`(?:...)`	Create a group but do not capture
`(a\|b)`	a or b
`a?`	Zero or one of a
`a*`	Zero or more of a
`a+`	One or more of a
`a{3}`	Exactly 3 of a
`a{3,}`	3 or more of a
`a{3,6}`	Between 3 and 6 of a

$pattern options

`i`	case insensitive
`m`	treat as multi-line string
`s`	dot matches newline
`x`	ignore whitespace in regex
`A`	matches only at the start of string
`D`	matches only at the end of string
`U`	non-greedy matching by default

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