PHP implements the method of replacing only once or N times

This article mainly introduces the method of replacing only once or N times in PHP. Interested friends can refer to it. I hope it will be helpful to everyone.

Method 1: str_replace_once
IdeaFirst find the location of the keyword to be replaced, and then use the substr_replace function to directly replace it .

<?php
function str_replace_once($needle, $replace, $haystack) {
// Looks for the first occurence of $needle in $haystack
// and replaces it with $replace.
$pos = strpos($haystack, $needle);
if ($pos === false) {
// Nothing found
return $haystack;
}
return substr_replace($haystack, $replace, $pos, strlen($needle));
}
?>

Method 2, str_replace_limit
Idea Still use preg_replace, but its parameters are more like preg_replace, and for certain Some special characters have been escaped for better versatility.

<?
function str_replace_limit($search, $replace, $subject, $limit=-1) {
// constructing mask(s)...
if (is_array($search)) {
foreach ($search as $k=>$v) {
$search[$k] = &#39;`&#39; . preg_quote($search[$k],&#39;`&#39;) . &#39;`&#39;;
}
}
else {
$search = &#39;`&#39; . preg_quote($search,&#39;`&#39;) . &#39;`&#39;;
}
// replacement
return preg_replace($search, $replace, $subject, $limit);
}
?>

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