AutoHotkey Community

In desperate need of a fast way to convert a large base 10 number into base 36.

Have searched the forum and found all other conversions, but not base 36, can anyone assist??????

...or a single line recursive function

Thanks worked like a charm, you are indeed a genius.

Thanks again.

Amen!

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"Power can be given overnight, but responsibility must be taught. Long years go into its making."

it stops working when passed a float. i suggest:

ToBase(n,b)
{
; n >= 0, 1 < b <= 36
if n is not integer
return "error"
Return (n < b ? "" : ToBase(n//b,b)) . ((d:=mod(n,b)) < 10 ? d : Chr(d+55))
}

Nice function, as always Laszlo!

Do recursive functions work efficiently (faster than loop?) and safely (stack overflow?) in AutoHotKey?

I know that C and other languages will try to optimize recursive functions, such as with tail recursion, but does AHK?

Also, when you say octal, do you mean decimal or truly octal (base values?

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These functions demonstrate the algorithms. If you want to put them in a library, of course, some error checking is needed.
Loops are faster, but these functions are not meant to be used in time critical applications, but to convert a few numbers, like in a calculator. If you need speed, you have to use machine code functions, instead.

AHK allows hundreds of levels of recursion with its standard settings. In our case, each call results in a new digit, so there will never be more than 64 levels of the recursion, therefore it is safe.
Base 8.

BTW, sorry about that last question. I misread that comment as meaning acceptable inputs were hex and oct for some reason. :S

Thanks, I'll have to add this to my \Libs. Source citation, yourself?

Edit: Would you mind expanding on this, to allow for in-base and out-base? ie, converting base36 back to base10. My method depends on converting to a neutral common base (base 10) before converting to another. eg: base(xyzzy, 36, 16) would convert xyzzy from base36 to base10 to base16. I'm certain you could cut out the middle-man.

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As I said, the above functions were meant to demonstrate the algorithms. The base conversion functions are built into the C run time library supplied with Windows. You only need a wrapper:

@Laszlo,

cool stuff. (Amazing how ignorant I feel sometimes when looking at your stuff)...

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Joyce Jamce

I must say, Lazlo, you owned your first post with your second one's code. lol

Thanks, guys, but I use the third function (the wrapper for msvcrt) in my popup calculator. It is the fastest and small, although has no educational value.

So now you must educate me on how to write a base algorithm that converts baseA to baseB without stopping at base10 in between. No nested loops, no recursion, just math.

The wrapper version stops at binary in between, not base 10. Most computers do internal arithmetic in only a few bases (binary, BCD…), so you need to stop there, unless you want to emulate arbitrary base arithmetic. It would be complicated and slow, so why do you want it? To learn how long division works?