Velocity Reviews > How to convert an hex string to a Hex number

# How to convert an hex string to a Hex number

chirs
Guest
Posts: n/a

 12-01-2003
Hi,

I'd like to use a var to hold a Hex number. But in this code:

var a = "ffff00"

a is a string. var a=ffff00 will not work either. How can I put a
Hex number ffff00 into a var?

Thanks

Chris

Lasse Reichstein Nielsen
Guest
Posts: n/a

 12-01-2003
http://www.velocityreviews.com/forums/(E-Mail Removed) (chirs) writes:

> I'd like to use a var to hold a Hex number. But in this code:
>
> var a = "ffff00"
>
> a is a string. var a=ffff00 will not work either. How can I put a
> Hex number ffff00 into a var?

var a = 0xffff00;

In Javascript, and most other languages with a C like syntax,
hexadecimal numbers are written with a prefix "0x".

--
Lasse Reichstein Nielsen - (E-Mail Removed)
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleDOM.html>
'Faith without judgement merely degrades the spirit divine.'

Douglas Crockford
Guest
Posts: n/a

 12-01-2003
> I'd like to use a var to hold a Hex number. But in this code:
>
> var a = "ffff00"
>
> a is a string. var a=ffff00 will not work either. How can I put a
> Hex number ffff00 into a var?

Buy a book. You can't program in total ignorance. I recommend Flanagan's
Definitive Guide (4th Ed) from O'Reilly.

Try

var a = 0xffff00;

http://www.crockford.com/javascript/javascript.html

Dr John Stockton
Guest
Posts: n/a

 12-01-2003
JRS: In article <(E-Mail Removed)> , seen
in news:comp.lang.javascript, chirs <(E-Mail Removed)> posted at Sun, 30
Nov 2003 21:36:27 :-
>
>I'd like to use a var to hold a Hex number.

Variables hold IEEE Doubles as the only form of number, except maybe in
future. You can, however, use Hex notation to specify the contents of a
variable.

> But in this code:
>
>var a = "ffff00"
>
>a is a string. var a=ffff00 will not work either. How can I put a
>Hex number ffff00 into a var?

var a = 0xffff00 // 1. to give a literal in Hex

var HS = "ffff00"

var a = +("0x"+HS) // 2. using existing string

var a = parseInt(HS, 16) // 3. normal, using existing string

Here 2 & 3 give different result with different illegal strings HS; try
"fated" & "defeat"; I prefer the former.

--
<URL:http://jibbering.com/faq/> Jim Ley's FAQ for news:comp.lang.javascript
<URL:http://www.merlyn.demon.co.uk/js-index.htm> JS maths, dates, sources.