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ereg_replace

Replace regular expression (PHP 4, PHP 5)
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 1891. 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 1892. 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 1893. 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().