preg_split
(PHP 4, PHP 5)
preg_split — Split string by a regular expression
Description
Split the given string by a regular expression.
Parameters
- pattern
-
The pattern to search for, as a string.
- subject
-
The input string.
- limit
-
If specified, then only substrings up to limit are returned with the rest of the string being placed in the last substring. A limit of -1, 0 or null means "no limit" and, as is standard across PHP, you can use null to skip to the flags parameter.
- flags
-
flags can be any combination of the following flags (combined with the | bitwise operator):
- PREG_SPLIT_NO_EMPTY
- If this flag is set, only non-empty pieces will be returned by preg_split().
- PREG_SPLIT_DELIM_CAPTURE
- If this flag is set, parenthesized expression in the delimiter pattern will be captured and returned as well.
- PREG_SPLIT_OFFSET_CAPTURE
-
If this flag is set, for every occurring match the appendant string offset will also be returned. Note that this changes the return value in an array where every element is an array consisting of the matched string at offset 0 and its string offset into subject at offset 1.
Return Values
Returns an array containing substrings of subject split along boundaries matched by pattern.
Changelog
| Version | Description |
|---|---|
| 4.3.0 | The PREG_SPLIT_OFFSET_CAPTURE was added |
| 4.0.5 | The PREG_SPLIT_DELIM_CAPTURE was added |
Examples
Example #1 preg_split() example : Get the parts of a search string
<?php
// split the phrase by any number of commas or space characters,
// which include " ", \r, \t, \n and \f
$keywords = preg_split("/[\s,]+/", "hypertext language, programming");
?>
Example #2 Splitting a string into component characters
<?php
$str = 'string';
$chars = preg_split('//', $str, -1, PREG_SPLIT_NO_EMPTY);
print_r($chars);
?>
Example #3 Splitting a string into matches and their offsets
<?php
$str = 'hypertext language programming';
$chars = preg_split('/ /', $str, -1, PREG_SPLIT_OFFSET_CAPTURE);
print_r($chars);
?>
The above example will output:
Array
(
[0] => Array
(
[0] => hypertext
[1] => 0
)
[1] => Array
(
[0] => language
[1] => 10
)
[2] => Array
(
[0] => programming
[1] => 19
)
)
Notes
If you don't need the power of regular expressions, you can choose faster (albeit simpler) alternatives like explode() or str_split().
See Also
- spliti() - Split string into array by regular expression case insensitive
- split() - Split string into array by regular expression
- implode() - Join array elements with a string
- preg_match() - Perform a regular expression match
- preg_match_all() - Perform a global regular expression match
- preg_replace() - Perform a regular expression search and replace
- preg_last_error() - Returns the error code of the last PCRE regex execution