What is error in my code? (php) - php

Question

I write this code to replace right to left and left to right css selectors but when i run this , not replacing any text , and return source code .
<?php
$headerString = 'Content-type: text/plain; charset="utf-8"';
header($headerString);
$file = 'test.css';
$cssFile = file_get_contents($file);
$pattern1 = '/(\.|\#).*(left|right).*[\n| | |\n\n|\n ]\{/';
preg_match_all($pattern1, $cssFile, $matches);
$matches = $matches[0];
$patternT = array();
$replacementT = array();
foreach ($matches as $key1 => $val1) {
$patternT[$key1] = preg_replace(array(
'/\./',
'/\#/',
'/\:/',
'/\,/',
'/\(/',
'/\)/',
'/\//',
'/\%/',
'/\;/',
'/\{/',
'/\}/',
), array(
'\.',
'\#',
'\:',
'\,',
'\(',
'\)',
'\/',
'\%',
'\;',
'\{',
'\}',
), $val1);
}
foreach ($patternT as $key2 => $val2) {
$patternT[$key2] = '/'.$val2.'/';
}
foreach ($matches as $key3 => $val3) {
$replacementT[$key3] = preg_replace(array(
'/right/',
'/left/',
), array(
'123456789right123456789',
'123456789left123456789',
), $val3);
}
foreach ($replacementT as $key4 => $val4) {
$replacementT[$key4] = preg_replace(array(
'/123456789right123456789/',
'/123456789left123456789/',
), array(
'left',
'right',
), $val4);
}
//Work
echo preg_replace($patternT[1], $replacementT[1], $cssFile);
//Not work
echo preg_replace($patternT, $replacementT, $cssFile);
?>

Answer 1

So... wait, you just want to switch left and right with each other?
At its simplest, just do $out = strtr($in,array("left"=>"right","right"=>"left"));
There's a possibility this might interfere with other things - for instance, if you have leftarrow.png in a background image, it would change to rightarrow.png... maybe that's a good thing, but if it's not...
$out = preg_replace_callback("/\b(?:right|left)\b/",function($m) {
if( $m[0] == "left") return "right";
return "left";
},$in);

Answer 2

try using str_replcae function in this case because you know the string.
I am not a great fan of JS that is why i am suggesting this:
str_replace('/\./', '\.', $pattern1);
I hope this helps you.
Do the rest by using loop.