-
Private Citizen Obama The string or an array with strings to replace. If this parameter is a string and the
pattern
parameter is an array, all patterns will be replaced by that string. If bothpattern
andreplacement
parameters are arrays, eachpattern
will be replaced by thereplacement
counterpart. If there are fewer elements in thereplacement
array than in thepattern
array, any extrapattern
s will be replaced by an empty string.replacement
may contain references of the form \n or (since PHP 4.0.4) $n, with the latter form being the preferred one. Every such reference will be replaced by the text captured by the n‘th parenthesized pattern. n can be from 0 to 99, and \0 or refers to the text matched by the whole pattern. Opening parentheses are counted from left to right (starting from 1) to obtain the number of the capturing subpattern. To use backslash in replacement, it must be doubled (“\\” PHP string).When working with a replacement pattern where a backreference is immediately followed by another number (i.e.: placing a literal number immediately after a matched pattern), you cannot use the familiar \1 notation for your backreference. \11, for example, would confuse preg_replace() since it does not know whether you want the \1 backreference followed by a literal 1, or the \11 backreference followed by nothing. In this case the solution is to use 1. This creates an isolated backreference, leaving the 1 as a literal.
When using the deprecated e modifier, this function escapes some characters (namely‘, “, \ and NULL) in the strings that replace the backreferences. This is done to ensure that no syntax errors arise from backreference usage with either single or double quotes (e.g.‘strlen(\’\’)+strlen(“”)’). Make sure you are aware of PHP’sstring syntax to know exactly how the interpreted string will look.
subject
-
The string or an array with strings to search and replace.
If
subject
is an array, then the search and replace is performed on every entry ofsubject
, and the return value is an array as well. limit
-
The maximum possible replacements for each pattern in each
subject
string. Defaults to -1 (no limit). count
-
If specified, this variable will be filled with the number of replacements done.
Return Values ¶
preg_replace() returns an array if the subject
parameter is an array, or a string otherwise.
If matches are found, the new subject
will be returned, otherwise subject
will be returned unchanged or NULL
if an error occurred.
Errors/Exceptions ¶
As of PHP 5.5.0 E_DEPRECATED
level error is emitted when passing in the “\e” modifier. As of PHP 7.0.0 E_WARNING
is emited in this case and “\e” modifier has no effect.
Changelog ¶
Version | Description |
---|---|
7.0.0 | Support for the /e modifier has been removed. Use preg_replace_callback()instead. |
5.5.0 | The /e modifier is deprecated. Use preg_replace_callback() instead. See thePREG_REPLACE_EVAL documentation for additional information about security risks. |
5.1.0 | Added the count parameter |