[flexcoders] Re: swap two variables without temporary variable
carlos m wrote: Hey Reid, Don't think there is a built-in function that will do that for you--not that I am aware of anyway--but there is definitely a way of implementing it! Check out this blog post by the awesome guys at polygonal: http://lab.polygonal.de/2007/05/10/bitwise-gems-fast-integer-math/ . Specifically, check out the section labeled Swap integers without temporary variables using XOR. Lot's of goodies on that blog! Cliffnotes: var t:int = a; a = b; b = t; //equals: a ^= b; b ^= a; a ^= b;HTH! Hi Carlos, Thanks for the note -- I suppose I should have been more clear. I meant, how to swap two variables in one line: it's not about speed but rather clarity. :) Reid
RE: [flexcoders] Re: swap two variables without temporary variable
AS3 does not have references to ints. ints re always passed by value, so you cannot write a method like swap(a, b) to swap them. Just use a temp var. - Gordon From: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Reid Priedhorsky Sent: Thursday, August 30, 2007 9:41 AM To: flexcoders@yahoogroups.com Subject: [flexcoders] Re: swap two variables without temporary variable carlos m wrote: Hey Reid, Don't think there is a built-in function that will do that for you--not that I am aware of anyway--but there is definitely a way of implementing it! Check out this blog post by the awesome guys at polygonal: http://lab.polygonal.de/2007/05/10/bitwise-gems-fast-integer-math/ http://lab.polygonal.de/2007/05/10/bitwise-gems-fast-integer-math/ . Specifically, check out the section labeled Swap integers without temporary variables using XOR. Lot's of goodies on that blog! Cliffnotes: var t:int = a; a = b; b = t; //equals: a ^= b; b ^= a; a ^= b;HTH! Hi Carlos, Thanks for the note -- I suppose I should have been more clear. I meant, how to swap two variables in one line: it's not about speed but rather clarity. :) Reid
[flexcoders] Re: swap two variables without temporary variable
What about:
...
swap(this, a, b);
...
private function swap(o: *, propnameA: String, propnameB: String) :
void {
// pseudocode for the swap
temp = o[propnameA];
o[propnameA] = o[propnameB];
o[propnameB] = temp;
}
I guess it might depend on access to the variables within the object,
but shouldn't that always work for o == this?
Doug
--- In flexcoders@yahoogroups.com, Gordon Smith [EMAIL PROTECTED] wrote:
AS3 does not have references to ints. ints re always passed by
value, so
you cannot write a method like swap(a, b) to swap them. Just use a
temp
var.
- Gordon
From: flexcoders@yahoogroups.com
[mailto:[EMAIL PROTECTED] On
Behalf Of Reid Priedhorsky
Sent: Thursday, August 30, 2007 9:41 AM
To: flexcoders@yahoogroups.com
Subject: [flexcoders] Re: swap two variables without temporary
variable
carlos m wrote:
Hey Reid,
Don't think there is a built-in function that will do that for
you--not that I am aware of anyway--but there is definitely a way
of
implementing it! Check out this blog post by the awesome guys at
polygonal:
http://lab.polygonal.de/2007/05/10/bitwise-gems-fast-integer-math/
http://lab.polygonal.de/2007/05/10/bitwise-gems-fast-integer-
math/ .
Specifically, check out the section labeled Swap integers without
temporary variables using XOR.
Lot's of goodies on that blog!
Cliffnotes:
var t:int = a;
a = b;
b = t;
//equals:
a ^= b;
b ^= a;
a ^= b;HTH!
Hi Carlos,
Thanks for the note -- I suppose I should have been more clear. I
meant,
how to swap two variables in one line: it's not about speed but
rather
clarity. :)
Reid
