lecestan96 Posted November 8, 2014 Share Posted November 8, 2014 so im on chapter 4 of basic java and the teacher said his program implements a simple "decoder ring". It will prompt the user for a message to decode and decode the message based on the following substitution rules: ABCDEFGHIJKLMNOPQRSTUVWXYZ will map to ZEBRASCDFGHIJKLMNOPQTUVWXY abcdefghijklmnopqrstuvwxyz will also map to ZEBRASCDFGHIJKLMNOPQTUVWXY any other characters (like space, punctuation, will map to themselves) so if it sees an 'A' (or an 'a'), it will map to 'Z', etc i've tried switch statements and for loop and such but van't figure it out please help. Quote Link to comment Share on other sites More sharing options...
requinix Posted November 8, 2014 Share Posted November 8, 2014 Are you doing this in PHP or Java? Either way, post your code and describe what problems you're having with it. Quote Link to comment Share on other sites More sharing options...
QuickOldCar Posted November 8, 2014 Share Posted November 8, 2014 You want to replace one character with another. You can explode the string and do replaces that way. str_ireplace() or preg_replace() I chose another way. <?php $text = "A test string to see the output of this replace."; $loweralpha = range('a', 'z'); $upperalpha = range('A', 'Z'); $alpha = array_merge($loweralpha,$upperalpha); $replace = array('Z','E','B','R','A','S','C','D','F','G','H','I','J','K','L','M','N','O','P','Q','T','U','V','W','X','Y','Z','E','B','R','A','S','C','D','F','G','H','I','J','K','L','M','N','O','P','Q','T','U','V','W','X','Y'); echo strtr($text, array_combine($alpha, $replace)); ?> Returns Z QAPQ PQOFKC QL PAA QDA LTQMTQ LS QDFP OAMIZBA. Quote Link to comment Share on other sites More sharing options...
Barand Posted November 8, 2014 Share Posted November 8, 2014 You don't really want to create that replace array manually every time <?php $str = isset($_GET['str']) ? $_GET['str'] : ''; $kw = isset($_GET['keyword']) ? $_GET['keyword'] : ''; $decode = isset($_GET['decode']) ? 1 : 0; $str2 = $str ? translate($str, $kw, $decode) : $str; function translate($str, $kw, $decode=0) { $str = strtoupper($str); $alpha = range('A','Z'); $karr = keyArray($kw, $alpha); $trans = $decode ? array_combine($karr, $alpha) : array_combine($alpha, $karr); return strtr($str,$trans); } function keyArray($keyword, &$alpha) { // create translation array from given keyword $kw = array_unique(str_split(strtoupper($keyword))); $diff = array_diff($alpha, $kw); return array_merge($kw, $diff); } ?> <html> <head> <title>Encoder</title> </head> <body> <form> Input text/Translation<br> <textarea name="str" rows="5" cols="50"><?=$str2?></textarea> <br> Keyword <input type="text" name="keyword" value="<?=$kw?>"> Decode <input type='checkbox' name='decode' value='1'> <br> <input type="submit" name="btnSub" value="Translate"> </form> </body> </html> Quote Link to comment Share on other sites More sharing options...
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