preg_split
Split string by a regular expression
Description
arrayfalse preg_split(
string $pattern
,
string $subject
,
int $limit
= -1,
int $flags
= 0
)
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 or 0 means "no limit".
-
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
, or false
on failure.
Errors/Exceptions
If the regex pattern passed does not compile to a valid regex, an E_WARNING
is emitted.
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
$keywords = preg_split("/[\s,]+/", "hypertext language, programming");
print_r($keywords);
?>
The above example will output:
Array
(
[0] => hypertext
[1] => language
[2] => programming
)
Example #2 Splitting a string into component characters
<?php
$str = 'string';
$chars = preg_split('//', $str, -1, PREG_SPLIT_NO_EMPTY);
print_r($chars);
?>
The above example will output:
Array
(
[0] => s
[1] => t
[2] => r
[3] => i
[4] => n
[5] => g
)
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
Tip
If you don't need the power of regular expressions, you can choose
faster (albeit simpler) alternatives like explode
or str_split.
Tip
If matching fails, an array with a single element containing the input string will be returned.
See Also
- PCRE Patterns
- preg_quote
- implode
- preg_match
- preg_match_all
- preg_replace
- preg_last_error