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Index › Programming Questions & Help › Syntax Questions › How do u determine if result is a float or an int
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How do u determine if result is a float or an int? (Read 462 times)
rgbk
How do u determine if result is a float or an int?
Dec 15th, 2008, 1:50am  
If I divide my yPos by 5, and get a result which has a decimal point, ie a float, I want nothing to happen, if I divide the yPos by 5 and get an integer, i want something to happen.

How do I ask processing to check if a result is an integer or a float? Or a whole number or a number with decimals?

The purpose is to allow a line drawing script to work on a grid. So I only want the line to draw when it's on multiples of 5.

Thanks!
Marc
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koogy
Re: How do u determine if result is a float or an
Reply #1 - Dec 15th, 2008, 1:02pm  
is the thing you're dividing an int or a float?

the following works for integers

Code:

int y;
if ((y % 5) == 0) {
  // this is true for y = 0, 5, 10...
}
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PhiLho 
Re: How do u determine if result is a float or an
Reply #2 - Dec 15th, 2008, 2:10pm  
Actually, it works also for floats.
You can even do:
Code:
float f = 7.5;
println(f % 1.5); // Shows 0.0

Which leads to a trick to answer the title:
number % 1 == 0
is true if number is an integer (0 in the decimal part).
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koogy
Re: How do u determine if result is a float or an
Reply #3 - Dec 15th, 2008, 9:16pm  
i was told never to compare floating point numbers for equality - they just aren't accurate enough.

http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
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rgbk
Re: How do u determine if result is a float or an
Reply #4 - Dec 16th, 2008, 5:11pm  
Hi
Sorry been sick with flu thus my quietness.

I was thinking the modulo could be one of the ways to work it out. I know understand it, basically it works out the remainder left after dividing something in wholes, so if that remainder is zero, it's fully divisible by it. Handy!

Thanks a bunch.
Marc
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Eric F.
Re: How do u determine if result is a float or an
Reply #5 - Jan 29th, 2009, 7:14pm  
what about
Code:

if (f==floor(f)) {
   ...
}


also, just semantics - i would use terms "whole" and "non-whole" because "integer" and "float" are data types, and a whole number of 3.0 is still technically a float.  mathematically it's an integer, but in programming it's not.
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