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, and if limit is -1, it actually means "no limit", which is useful for specifying the flags .
- flags
-
flags can be any combination of the following flags (combined with 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 |
4.0.0 | The flags parameter 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().