ereg_replace
(PHP 4, PHP 5)
ereg_replace — Replace regular expression
Description
string ereg_replace
( string $pattern
, string $replacement
, string $string
)
This function scans string
for matches to
pattern
, then replaces the matched text
with replacement
.
Parameters
-
pattern
-
A POSIX extended regular expression.
-
replacement
-
If pattern
contains parenthesized substrings,
replacement
may contain substrings of the form
\\digit, which will be
replaced by the text matching the digit'th parenthesized substring;
\\0 will produce the entire contents of string.
Up to nine substrings may be used. Parentheses may be nested, in which
case they are counted by the opening parenthesis.
-
string
-
The input string.
Return Values
The modified string is returned. If no matches are found in
string
, then it will be returned unchanged.
Examples
For example, the following code snippet prints "This was a test"
three times:
Example #1 ereg_replace() example
<?php
$string = "This is a test";
echo str_replace(" is", " was", $string);
echo ereg_replace("( )is", "\\1was", $string);
echo ereg_replace("(( )is)", "\\2was", $string);
?>
One thing to take note of is that if you use an integer value as
the replacement
parameter, you may not get
the results you expect. This is because
ereg_replace() will interpret the number as
the ordinal value of a character, and apply that. For instance:
Example #2 ereg_replace() example
<?php
/* This will not work as expected. */
$num = 4;
$string = "This string has four words.";
$string = ereg_replace('four', $num, $string);
echo $string; /* Output: 'This string has words.' */
/* This will work. */
$num = '4';
$string = "This string has four words.";
$string = ereg_replace('four', $num, $string);
echo $string; /* Output: 'This string has 4 words.' */
?>
Example #3 Replace URLs with links
<?php
$text = ereg_replace("[[:alpha:]]+://[^<>[:space:]]+[[:alnum:]/]",
"<a href=\"\\0\">\\0</a>", $text);
?>
Notes
Tip
preg_replace(), which uses a Perl-compatible
regular expression syntax, is often a faster alternative to
ereg_replace().
