PHP: str_replace from end of string-CodePudding

This is my string:

Hello world Hello How are You Hello world

I want to replace last Hello world to HW

Result:

Hello world Hello How are You HW

str_replace replaces all Hello world but I want to replace from end (if exists)

CodePudding user response：

I guess you want to use a single function for this, but it doesn't exist. You can build your own function, like this:

<?php

function str_replace_last($search, $replace, $subject)
{
    $pos = strrpos($search,$replace);
    if ($pos === FALSE) return search;
    return substr($search, 0, $pos) . $subject . 
           substr($search, $pos   strlen($replace));
}

echo str_replace_last('Hello world Hello How are You Hello world', 
                      'Hello world', 'HW');

This returns:

Hello world Hello How are You HW

See: strrpos()

Note that this function doesn't work with array arguments as the original str_replace() does.

CodePudding user response：

If you want you can use preg_replace()

using the pattern Hello world$

<?php
$re = '/Hello world$/m';
$str = 'Hello world Hello How are You Hello world';

echo preg_replace($re, 'HW', $str);
?>

This would need the least code if do it in one line

preg_replace('/Hello world$/m','HW','Hello world Hello How are You Hello world');