(PHP 3 <= 3.0.18, PHP 4 >= 4.0.0)
ereg_replace -- Replace regular expression
Description
string ereg_replace (string pattern, string replacement, string
string)
Note: preg_replace(), which uses a
Perl-compatible regular expression syntax, is often a faster alternative to
ereg_replace().
This function scans string for matches to pattern, then
replaces the matched text with replacement.
The modified string is returned. (Which may mean that the original string is returned if
there are no matches to be replaced.)
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.
If no matches are found in string, then string will be
returned unchanged.
For example, the following code snippet prints "This was a test" three times:
|
Example 1. ereg_replace() Example
$string = "This is a test";
echo ereg_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
$text = ereg_replace("[[:alpha:]]+://[^<>[:space:]]+[[:alnum:]/]",
"<a href=\"\\0\">\\0</a>", $text);
|
|
See also ereg(),
eregi(), eregi_replace(), str_replace(), and
preg_match().
|
