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rnielsen
Joined: 23 Sep 2003
Posts: 852
Location: Utah
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| Odd or even number |
 Posted: Fri Jul 08, 2005 10:21 am |
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This may be a dumb question but what's an easy way to determine if a number(variable) is odd or even? 
Ronald |
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Ttelmah
Guest
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| Re: Odd or even number |
| Posted: Fri Jul 08, 2005 10:25 am |
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| rnielsen wrote: | This may be a dumb question but what's an easy way to determine if a number(variable) is odd or even?
Ronald |
For an integer, it couldn't be easier!. Use a bitwise '&' with '1'. If this is non-zero (true), the number is odd.
So:
| Code: |
#define isodd(x) ((x)&0x1L)
//Use this like:
if (isodd(value)) {
//Here the number was odd
}
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Best Wishes |
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sseidman
Joined: 14 Mar 2005
Posts: 159
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| Re: Odd or even number |
| Posted: Fri Jul 08, 2005 10:26 am |
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| rnielsen wrote: | This may be a dumb question but what's an easy way to determine if a number(variable) is odd or even?
Ronald |
Assuming an integer, if the LSB is zero, the number is even.
Scott |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Jul 08, 2005 10:26 am |
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| You just test the LSB. |
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kender
Joined: 09 Aug 2004
Posts: 768
Location: Silicon Valley
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| Posted: Fri Jul 08, 2005 10:51 am |
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| Code: |
if (n & 0x01)
{
// odd
}
else
{
// even
}
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rnielsen
Joined: 23 Sep 2003
Posts: 852
Location: Utah
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| Posted: Fri Jul 08, 2005 11:06 am |
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Thanks. I like the LSB bit test. Simple.
Ronald |
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Ttelmah
Guest
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| Posted: Fri Jul 08, 2005 3:21 pm |
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I have to wonder if this thread was actually a 'record'. Four answers, all with basically the same solution in one minute!. I have seen a couple of overlapped answers before, but four is pretty amazing. :-)
Given that the writers, can't see other answers 'in preparation', it shows a remarkable activity level on the group.
Best Wishes |
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| Posted: Fri Jul 08, 2005 3:49 pm |
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| Great minds think alike. |
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