int into string

[aximbigfan]

I need a function that will receive an int, and transform it into a letter representation.

 

PHP can do a neat thing, where it will increment a string, as so...

a

b

c

d

...

z

aa

ab

ac

ad

.

 

What I need to do, is convert this into an int. For example, aa would be 27, ab would be 28, a would be 1, b would be 2, you get it.

 

I also need to convert a number into this kind of representation.

 

Any ideas?

 

Thanks,

Chris

[Adam]

Quite complicated if you ask me, would take some thinking power! This topic may be better suited to the freelance section? Unless someone's done this before? I'll keep thinking but every idea I have at the minute is a dead end! Sorry pal!

 

Adam

[Mchl]

Just use str_replace

 

[edit]

 

Wrong  

 

But you could use ord and chr

[unkwntech]

@Mchl - that would require quite a lot of code as you would need one for each possible element.

[Mchl]

ord('a') = 97
ord('a') - 96 = 1
ord('b') - 96 = 2
...

ord($char) - 96 = $number

 

chr(1+96) = 'a'
chr($number + 96) = $char

[unkwntech]

Nice answer Mchl.... I didn't even know there was a ord() function.......

[Mchl]

  Quote

I didn't even know there was a ord() function.......

 

It exists in most programming languages (may be named differently)

[unkwntech]

True, but I guess I never needed it in PHP.

[sasa]

try

<?php
$text = 'u';
for ($i = 1; $i < 10; $i++) echo $text++,"\n";
?>

use ++ operator

[aximbigfan]

  Quote

try

<?php
$text = 'u';
for ($i = 1; $i < 10; $i++) echo $text++,"\n";
?>

use ++ operator

 

That's perfect!

 

Thanks Sasa!

 

Chris

[Mark Baker]

From PHPExcel:

    public static function columnIndexFromString($pString = 'A')
    {
    	// Convert to uppercase
    	$pString = strtoupper($pString);

    	// Convert column to integer
    	if (strlen($pString) == 1) {
    		return (ord($pString{0}) - 64);
    	} elseif (strlen($pString) == 2) {
    		return $result = ((1 + (ord($pString{0}) - 65)) * 26) + (ord($pString{1}) - 64);
    	} elseif (strlen($pString) == 3) {
		return ((1 + (ord($pString{0}) - 65)) * 676) + ((1 + (ord($pString{1}) - 65)) * 26) + (ord($pString{2}) - 64);
    	} else {
    		throw new Exception("Column string index can not be " . (strlen($pString) != 0 ? "longer than 3 characters" : "empty") . ".");
    	}
    }

    public static function stringFromColumnIndex($pColumnIndex = 0)
    {
        // Convert column to string
        $returnValue = '';
        // Determine column string
        if ($pColumnIndex < 26) {
        	$returnValue = chr(65 + $pColumnIndex);
        } else {
        	$iRemainder = (int)($pColumnIndex / 26) -1;
        	$returnValue = PHPExcel_Cell::stringFromColumnIndex($iRemainder).chr(65 + $pColumnIndex%26) ;
        }
        // Return
        return $returnValue;
    }