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@NogDogJan 30.2014 — #Sounds like you just need to change the else to an elseif, and put in that range as the condition? @NogDogFeb 01.2014 — #
PS: Feel free to change "and" to "&&" and "or" to "||", I just use the word forms out of habit, as I find them a bit easier both to read and type. ?@NogDogFeb 01.2014 — #Here's my revamped stab at it:
You do realize this would be extremely easy to decipher, right? ?@NogDogFeb 01.2014 — #Without seeing the code, no way to tell why it's outputting what it does where it does. ?@NogDogFeb 02.2014 — #Remove the echo command at the end of the encode file, and in the main file, use $encstring, not $newstring. ?
In fact, the way you are modularizing things (which is good) could be taken a step further, and putting the encode/decode stuff into functions that return the resulting strings, which you then would call in the main file; or even (gasp!) a class definition with encode() and decode() methods. ?@NogDogFeb 02.2014 — #In fact, here's how you might put it all into a single function, so that we can enforce the DRY (don't repeat yourself) principle:
To use it, just require() the file with that function definition, and then:
@NogDogFeb 02.2014 — #There's a bug in the above function, which is corrected in the following, where I decided to get all object-oriented on it:
sample usage:
Test output:
[RESOLVED] Caeser cipher help – excluding non-alphabetic characters
Hey everyone,
I wrote a Caesar cipher (a script where, given a message, the letters in the message are shifter x number of places; e.g. A => D, B => E, C => F, X => A, Y => B, Z => C, etc.). It works but it shifts [I]all
The script is here:
[code=php]<?php
for ($i=0; $i < strlen($string); $i++) {
$ascii = ord($string[$i]);
for ($j=0; $j < $sp; $j++) {
if ($ascii == 90) { //uppercase bound
$ascii = 65; //reset back to ‘A’
}
else if ($ascii == 122) { //lowercase bound
$ascii = 97; //reset back to ‘a’
}
else {
$ascii++;
}
}
$newstring[$i] = chr($ascii);
$encstring = $newstring;
}
?>
Any help would be appreciated as I can’t figure it out. If you want to see it in action it’s [URL=”http://avondaleriverside.com”]here
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0
@NogDogJan 30.2014 — #0
@NogDogFeb 01.2014 — #[code=php]
esleif ( ($ascii >= 65 and $ascii <= 90) or ($ascii >= 97 or $ascii <= 122 ) ) {
[/code]PS: Feel free to change "and" to "&&" and "or" to "||", I just use the word forms out of habit, as I find them a bit easier both to read and type. ?
0
@NogDogFeb 01.2014 — #Here's my revamped stab at it:[code=php]
<?php
$sp = 5;
$string = "Testing 1, 2, 3, and X, y, Z. All done!";
$newstring = array();
for ($i=0; $i < strlen($string); $i++) {
$ascii = ord($string[$i]);
if ($ascii < 65 || ($ascii > 90 && $ascii < 97) || $ascii > 122) {
$newstring[$i] = $string[$i];
}
else {
for ($j=0; $j < $sp; $j++) {
$ascii += 1;
if ($ascii == 91 or $ascii == 123) {
$ascii -= 26;
}
}
$newstring[$i] = chr($ascii);
}
}
$encstring = implode('', $newstring);
echo $encstring;
[/code]You do realize this would be extremely easy to decipher, right? ?
0
@NogDogFeb 01.2014 — #Without seeing the code, no way to tell why it's outputting what it does where it does. ?0
@NogDogFeb 02.2014 — #Remove the echo command at the end of the encode file, and in the main file, use $encstring, not $newstring. ?In fact, the way you are modularizing things (which is good) could be taken a step further, and putting the encode/decode stuff into functions that return the resulting strings, which you then would call in the main file; or even (gasp!) a class definition with encode() and decode() methods. ?
0
@NogDogFeb 02.2014 — #In fact, here's how you might put it all into a single function, so that we can enforce the DRY (don't repeat yourself) principle:[code=php]
<?php
/**
* pseudo encrypt/decrypt a string
* @return string
* @param string $string text to be encoded/decoded
* @param int $offset number of positions to offset letters (only)
*/
function caesar_cipher($string, $offset)
{
if(!ctype_digit($offset)) {
throw new Exception("offset must be an integer");
}
$newstring = array();
for ($i=0; $i < strlen($string); $i++) {
$ascii = ord($string[$i]);
if ($ascii < 65 || ($ascii > 90 && $ascii < 97) || $ascii > 122) {
$newstring[$i] = $string[$i];
}
else {
for ($j=0; $j < abs($offset); $j++) {
$ascii += 1;
if($offset > 0 and ($ascii == 91 or $ascii == 123)) {
$ascii -= 26;
}
elseif($ascii == 65 or $ascii == 97) { // negative offset
$ascii += 26;
}
}
$newstring[$i] = chr($ascii);
}
}
$encstring = implode('', $newstring);
return $encstring;
}
[/code]To use it, just require() the file with that function definition, and then:
[code=php]
$string = "whatever...";
$sp = 5;
$encrypted = caesar_encrypt($string, $sp);
$decrypted = caesar_encrypt($string, $sp * -1); // just negate the original offset
[/code]0
@NogDogFeb 02.2014 — #There's a bug in the above function, which is corrected in the following, where I decided to get all object-oriented on it:[code=php]
<?php
/**
* Provide a simple pseudo encryption of text only affecting [A-Za-z]
*/
class CaesarCipher
{
/**
* Encrypt it
* @return string
* @param string $string
* @param int $offset
*/
public function encrypt($string, $offset)
{
return $this->execute($string, $offset);
}
/**
* Decrypt it
* @return string
* @param string $string
* @param int $offset
*/
public function decrypt($string, $offset)
{
return $this->execute($string, $offset * -1);
}
/**
* pseudo encrypt/decrypt a string
* @return string
* @param string $string text to be encoded/decoded
* @param int $offset number of positions to offset letters (only)
*/
private function execute($string, $offset)
{
if(!is_int($offset)) {
throw new Exception("offset must be an integer");
}
// need to use this to fix bug:
$inc = 1;
if($offset < 0) {
$inc = -1;
}
$newstring = array();
for ($i=0; $i < strlen($string); $i++) {
$ascii = ord($string[$i]);
if ($ascii < 65 || ($ascii > 90 && $ascii < 97) || $ascii > 122) {
$newstring[$i] = $string[$i];
}
else {
for ($j=0; $j < abs($offset); $j++) {
$ascii += $inc;
if($offset > 0 and ($ascii == 91 or $ascii == 123)) {
$ascii -= 26;
}
elseif($ascii == 64 or $ascii == 96) { // negative offset
$ascii += 26;
}
}
$newstring[$i] = chr($ascii);
}
}
return implode('', $newstring);
}
}
[/code]sample usage:
[code=php]
$text = "ABCDE, abcde, UVWXYZ, uvwxyz, 123.";
$sp = 4;
$crypt = new CaesarCipher();
echo "<p>Start:<br />$text</p>n";
$text = $crypt->encrypt($text, $sp);
echo "<p>Encrypted:<br />$text</p>n";
$text = $crypt->decrypt($text, $sp);
echo "<p>Decrypted:<br />$text</p>n";
[/code]Test output:
Start:
ABCDE, abcde, UVWXYZ, uvwxyz, 123.
Encrypted:
EFGHI, efghi, YZABCD, yzabcd, 123.
Decrypted:
ABCDE, abcde, UVWXYZ, uvwxyz, 123.
[/quote]