Replace character and swap with the next one in string. - php

Question

i want to replace a char and want to put that character just after next char in php.
for example:
<?php
$exa = array("R" => "r", "A" => "a", "V" => "v", "I" => "i");
echo strtr("RAVI", $exa);
?> //displays "ravi" ok
i want to replace "V" with "v" and then want to put it after "I".
like this: "raiv"

Answer 1

I think this solution might interest you:
Function
function replaceAndMove($text, $replacements) {
$from = array_keys($replacements);
$to = array_values($replacements);
function fixFrom($s) {
return '/' . preg_quote($s, '/') . '(.|$)' . '/';
}
function fixTo($s) {
return '${1}' . $s;
}
$from_ready = array_map('fixFrom', $from);
$to_ready = array_map('fixTo', $to);
return preg_replace($from_ready, $to_ready, $text);
}
Test Case
$text = "abcdXefghXijklX----aFb~~~cMd";
$replacements = array(
'X' => 'x',
'F' => 'f',
'M' => 'm',
);
echo $text . '<br>';
echo replaceAndMove($text, $replacements);
Output
abcdXefghXijklX----aFb~~~cMd
abcdexfghixjkl-x---abf~~~cdm
Edit: Fixed problems with regex-special chars, such as . or ]

Answer 2

do the str_replace first, then use strlen, substr and the index of the character string to replace the last 2 spots if that is what you are trying to do. Because you can access a string like an array each characters $t[1] == e if the string was "test"
If you have a few "set" patterns you could just do this:
$find = array('RAVI',...,so on);
$replace = array('raiv',..., so on);
$input = 'RAVI';
echo str_replace($find, $replace, $input);
Just add more set pairs to the arrays for more replacements... If that's all you want.

Answer 3

Are you looking for something like this:
<?php
$string = "RAVIVL";
$replace_char = "v";
$string = strtolower($string);
$pos = array_keys(array_intersect(str_split($string),array($replace_char)));
foreach ($pos as $p) {
if (isset($string[$p+1])) {
$string[$p] = $string[$p+1];
$string[$p+1] = $replace_char;
}
}
echo $string;
?>
Swaps all occurrences o "v" with the following letter.