How to replace a letter in a string with a new letter that will not be updated

Question

Lets say I have some code:

$text = $_POST[\'secret\'];

$replaces = array(
        \'a\' => \'s\',
        \'b\' => \'n\',
        \'c\' => \'v\',
          


        

Answer 1

<?php
$text = $_POST['secret'];

$replaces = array(
    'a' => 's',
    'b' => 'n',
    'c' => 'v',
    'd' => 'f',
    'e' => 'r',
    'f' => 'g',
    'g' => 'h',
    'h' => 'j',
    'i' => 'o',
    'j' => 'k',
    'k' => 'l',
    'l' => 'a',
    'm' => 'z',
    'n' => 'm',
    'o' => 'p',
    'p' => 'q',
    'q' => 'w',
    'r' => 't',
    's' => 'd',
    't' => 'y',
    'u' => 'i',
    'v' => 'b',
    'w' => 'e',
    'x' => 'c',
    'y' => 'u',
    'z' => 'x',
);

for( $i=0,$l=strlen($text);$i<$l;$i++ ){
    if( isset($replaces[$text[$i]]) ){
        $text[$i] = $replaces[$text[$i]];
    }
}

echo "You're deciphered message is: ".$text;

?>

<form action="" method="post">
<p>Enter the secret message: <input name="secret" type="text"/></p>
<input class="button" type="submit" name="submit" value="Submit"/>

</form>

Answer 2

this will be your solution

   $text1 = '';
   for($i=0; $i<strlen($text); $i++)  {
     $text1 .= $replaces[$text[$i]];
   }

   echo $text1;

or else you can use like this

$text = strtr($text,$replaces);

Answer 3

In the PHP Manual it's clearly explained your problem, at the end of the page they advice to use strtr() which does exactly what you want.

Replace

  $text = str_replace(array_keys($replaces),array_values($replaces),$text);

with

  $text = strtr($text,$replaces);

which does exactly what you want, it replaces one character with another character.

The documentation of strtr() is here: http://www.php.net/manual/en/function.strtr.php