floating point value

heyas,

i was wondering if theres a way to determind if a float has a decimal value?

i.e i might have the following times

24:00
09:00
14:30

i want to know if i can iterate through an array or any collection and test if the '.30' exists.

or even more simply a function like isDecimal()

tia

-twans

my appologies,

those times should read:

24.00
09.00
14.30

as im storing them as floats! :P

If the number minus the floor of the number is anything other than zero, then there are values stored after the decimal place.

The only thing I can think of, is to subtract .30 from the number, and then use the modulus operator with a 1. If it was n.30, your answer will be 1.

Remember though, that floating point values can never be trusted to be exact, so don't use the == operator to test if it's 1. You could find the absolute value of (1 - yourNumber), and then test to see if that number is less then .1 or something.

works a charm,

those that are interested

Code:

#include <cmath>

floor(float);

thanks for your help josh

-twan

[edit: silly typo on the include]

You're welcome.

The standard library function floor() is in <cmath>. What is <floor>?

can the modulus operator be used on floats?

-thanks for the reply too sean.

Modulus only works on ints I believe.

You could get dirty and cast to int and back to float... something like this:

Code:

float x = 3.2f;
bool hasDecimal = x != (float)((int)x);

Note: this code hasn't been tested, I just wanted to get the idea across

There's an fmod(float x, float y) function in <cmath> that returns the remainder of x/y.

Originally Posted by twans

can the modulus operator be used on floats?

-thanks for the reply too sean.

Use the fmod function to calculate modulus on floating-point values.

[edit]Darn... beaten! [/edit]