Increment a Letter

[Zych]

Hello All,

I am just starting to play with AutoIt and find it very interesting. However I cannot find a way to increment a letter. For example, in my script, I want to map some drive letters. I made an ini file that has the starting drive letter. Let's then say I have four mappings to do. So let's say that in my ini file it has the letter "M". So I want to map "M", "N", "O", and "P". How can I increment M to get N? I could not find this in the help guide or through a Google search. Probably pretty easy but not sure how to do it.

Thanks,

Zych

[Fulano]

You have to cast it to an ascii value and then increment, then switch it back to a character. Keep in mind this will not wrap around from Z to a or z to A, so be sure to do some checks on your data so you don't end up trying to access drive [:\

Chr (Asc ("A") + 1)

Edit: Woot! props to Mavis Beacon

Edited March 24, 2010 by Fulano

[PsaltyDS]

You want a numeric value for the letter, which you can get from ASC() or ASCW(). Increment by one with the '+= 1' operator. Then convert back to a letter with Chr() or ChrW():

$sLast = "M"
$iASCII = Asc($sLast)
$iASCII += 1
$sNext = Chr($iASCII)
ConsoleWrite("Next letter = " & $sNext & @LF)

That can be shortened, but the longhand method illustrates it better. You would also want some error checking to be sure you didn't go past "Z" and "[" for a mapping letter.

Edit: Out-typed by Fulano, but at least we both beat Melba to it!

Edited March 24, 2010 by PsaltyDS

[Melba23]

Zych,

Welcome to the AuotIt forum.

Use Asc to get a numeric representation of the letter and then when you have increased it turn it back into a letter with Chr like this:

$sDrive = "M"

$iAscDrive = Asc($sDrive)

MsgBox(0, "ASCII", "m = " & $iAscDrive)

For $i = 1 To 3

    MsgBox(0, "Letters", "Next Drive: " & Chr($iAscDrive + $i))

Next

Ask if anything is unclear.

M23

[Zych]

WOW you guys are fast. Thank you very much.

[Fulano]

Np, we're kinda weird, playing with code is fun