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Itterating - "a" through "zzzz"

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Itterating - "a" through "zzzz"

Sep 1st, 2009

Hi all. I'm attempting to output all of the possible combination from "a" to "zzzz" and I'm wondering if theres an easy way of doing that. As an example output would be ...

a
b
c
....
z
aa
ab
ac
....
az
ba
bb
...

and so on..

Is there a way to just have a binary or hex value, cast it as an ascii to get your first value, then increment it and cast it again.. and so on?

Any help would be much appreciated.

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Re: Itterating - "a" through "zzzz"

Sep 2nd, 2009

This is how I would do it:

 Help with Code Tags 
 PHP Syntax (Toggle Plain Text) 
$lower = true; //if you want lowercase letters
$t = 4;
$s = 1;
while( $s <= $t ) {
	$i = ( $lower ? 97 : 65 );
	while( $i <= ( $lower ? 122 : 90 ) ) {
		echo str_repeat( chr( $i ),$s ) . '<br />';
		$i++;
	}
	$s++;
}
$lower = true; //if you want lowercase letters
$t = 4;
$s = 1;
while( $s <= $t ) {
	$i = ( $lower ? 97 : 65 );
	while( $i <= ( $lower ? 122 : 90 ) ) {
		echo str_repeat( chr( $i ),$s ) . '<br />';
		$i++;
	}
	$s++;
}

That what you are talking about?

Last edited by kkeith29; Sep 2nd, 2009 at 2:00 am.

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Use [code] tags.

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Re: Itterating - "a" through "zzzz"

Sep 2nd, 2009

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Originally Posted by kkeith29

This is how I would do it:
Help with Code Tags

PHP Syntax (Toggle Plain Text)
$lower = true; //if you want lowercase letters
$t = 4;
$s = 1;
while( $s <= $t ) {
	$i = ( $lower ? 97 : 65 );
	while( $i <= ( $lower ? 122 : 90 ) ) {
		echo str_repeat( chr( $i ),$s ) . '<br />';
		$i++;
	}
	$s++;
}
$lower = true; //if you want lowercase letters $t = 4; $s = 1; while( $s <= $t ) { $i = ( $lower ? 97 : 65 ); while( $i <= ( $lower ? 122 : 90 ) ) { echo str_repeat( chr( $i ),$s ) . '<br />'; $i++; } $s++; }
That what you are talking about?

Well sorta.. It would basically generate all teh combinations of a set containing 'a' through 'z'. i.e. {a,b,c,...,z}. So it owuldnt just generate aa, bb, cc.. it would go through all the possible combinations with a as the first character then b as the second character and so on.. sorry if I was not specific enough in my initial post.

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Re: Itterating - "a" through "zzzz"

Sep 2nd, 2009

This code below will do the trick, but it's going to use a lot of memory to run this.
You are making 26 x 26 x 26 x 26 = 456976 combinations. Are you sure you want to generate all of these combinations? What are you trying to achieve this for?

 Help with Code Tags 
 php Syntax (Toggle Plain Text) 
<?
for($a = 97; $a <= 122; $a++) /* 97 to 122 are the relevant ascii numbers */
{
	for($b = 97; $b <= 122; $b++)
	{
		for($c = 97; $c <= 122; $c++)
		{
			for($d = 97; $d <= 122; $d++)
			{
				echo chr($a).chr($b).chr($c).chr($d)."<br/>";
			}
		}
	}
}
?>
<?
for($a = 97; $a <= 122; $a++) /* 97 to 122 are the relevant ascii numbers */
{
	for($b = 97; $b <= 122; $b++)
	{
		for($c = 97; $c <= 122; $c++)
		{
			for($d = 97; $d <= 122; $d++)
			{
				echo chr($a).chr($b).chr($c).chr($d)."<br/>";
			}
		}
	}
}
?>

Regards,

Simon Mayer
Website design by Ribbontree

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Re: Itterating - "a" through "zzzz"

Sep 2nd, 2009

In fact, I realise that the above code will not produce your single, double and triple character strings.
There are more elegant ways of doing it, but I am not able to put the time into devising one at the moment. One way would be just to repeat the code like so:

 Help with Code Tags 
 php Syntax (Toggle Plain Text) 
<?
for($a = 97; $a <= 122; $a++) /* 97 to 122 are the relevant ascii numbers */
{
	echo chr($a)."<br/>";
}
 
 
 
for($a = 97; $a <= 122; $a++) /* 97 to 122 are the relevant ascii numbers */
{
	for($b = 97; $b <= 122; $b++)
	{
		echo chr($a).chr($b)."<br/>";
	}
}
 
 
 
for($a = 97; $a <= 122; $a++) /* 97 to 122 are the relevant ascii numbers */
{
	for($b = 97; $b <= 122; $b++)
	{
		for($c = 97; $c <= 122; $c++)
		{
			echo chr($a).chr($b).chr($c)."<br/>";
		}
	}
}
 
 
for($a = 97; $a <= 122; $a++) /* 97 to 122 are the relevant ascii numbers */
{
	for($b = 97; $b <= 122; $b++)
	{
		for($c = 97; $c <= 122; $c++)
		{
			for($d = 97; $d <= 122; $d++)
			{
				echo chr($a).chr($b).chr($c).chr($d)."<br/>";
			}
		}
	}
}
?>
<?
for($a = 97; $a <= 122; $a++) /* 97 to 122 are the relevant ascii numbers */
{
	echo chr($a)."<br/>";
}



for($a = 97; $a <= 122; $a++) /* 97 to 122 are the relevant ascii numbers */
{
	for($b = 97; $b <= 122; $b++)
	{
		echo chr($a).chr($b)."<br/>";
	}
}



for($a = 97; $a <= 122; $a++) /* 97 to 122 are the relevant ascii numbers */
{
	for($b = 97; $b <= 122; $b++)
	{
		for($c = 97; $c <= 122; $c++)
		{
			echo chr($a).chr($b).chr($c)."<br/>";
		}
	}
}


for($a = 97; $a <= 122; $a++) /* 97 to 122 are the relevant ascii numbers */
{
	for($b = 97; $b <= 122; $b++)
	{
		for($c = 97; $c <= 122; $c++)
		{
			for($d = 97; $d <= 122; $d++)
			{
				echo chr($a).chr($b).chr($c).chr($d)."<br/>";
			}
		}
	}
}
?>

Regards,

Simon Mayer
Website design by Ribbontree

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Re: Itterating - "a" through "zzzz"

Sep 16th, 2009

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Originally Posted by SimonMayer

This code below will do the trick, but it's going to use a lot of memory to run this.
You are making 26 x 26 x 26 x 26 = 456976 combinations. Are you sure you want to generate all of these combinations? What are you trying to achieve this for?

Thanks so much. Thats exactly what I was looking for. I am sorta unfamiliar with PHPs type casting syntax. I'm trying to stress test a script i'm preparing and just thought this would be a cool way to do it as well as a way to test myself and learn more.

Thanks again!