alphabetic sequence

anthill

I'm sure there is a simple solution to this, but I can't seem to find it. Basically, i'm trying to create a function where PHP will return the next value in its alphabetic sequence.

E.g.

Lets say I have an array, or database list of:

aaaa
aaab
aaac
aaad

I want it to look at those, and print the next in line, i.e. aaae

The same if it keeps going to:

aaaz
aaba
aabb....it wil return the next as aabc

and so on until you have zzzz

Thanks for taking time to read this.

Ant

sidney

using a database you would use ORDER BY in query and the database would return the results in order

if using an array you would use the sort, asort, usort or array_multi_sort etc functions of php

sort fuction will find links to other functions here to

anthill

Cheers Sid,

That's fine for ordering the results alphabetically, but what if I want it to automatically create the next in sequence, and then add this to the database?

i.e. connects to database containing the following values in a table.

abch
abcd
abcg
abcf
abce

looks at these, orders them correctly:

abcd
abce
abcf
abcg
abch

and then creates the next value:

abci

and then adds this to the database. So if you repeated the operation, the next time it would add abcj to the database, and so on.

Cheers

Ant

anthill

d'oh

$var = "abce";

$var++;

echo $var //gives me abcf

crimaniak

define('FIRST','a');
define('LAST','z');

/// using: $s=nextValue($s);
function nextValue($s)
{
	for($i=strlen($s)-1;$i>-1 && $s[$i]===LAST;--$i)
		$s[$i]=FIRST;
	if($i==-1)
		return FIRST.$s;
	$s[$i]=chr(ord($s[$i])+1);
	return $s;
}

/// using: usort($a,'ff');

function ff($a,$b)
{
	if(($l=strlen($a))!==strlen($b))
		return strlen($a)-strlen($b);

for($i=0;$i<$l-1 && $a[$i]===$b[$i];++$i);

return ord($a[$i])-ord($b[$i]);
}