(PHP 4, PHP 5)
ereg_replace — Replace regular expression
$pattern
, string $replacement
, string $string
)
This function scans string for matches to
pattern, then replaces the matched text
with replacement.
This function has been DEPRECATED as of PHP 5.3.0. Relying on this feature is highly discouraged.
patternA 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.
stringThe input string.
The modified string is returned. If no matches are found in
string, then it will be returned unchanged.
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);
?>
Note:
As of PHP 5.3.0, the regex extension is deprecated in favor of the PCRE extension. Calling this function will issue an
E_DEPRECATEDnotice. See the list of differences for help on converting to PCRE.
preg_replace(), which uses a Perl-compatible regular expression syntax, is often a faster alternative to ereg_replace().