Float is 0 after integer division

shannoga picture shannoga · Aug 15, 2012 · Viewed 10.2k times · Source

It might be a simple solution but I can not fix it.

I am dividing 2 integers :

finishedGameFinalScore = [score integerValue];
CGFloat interval = 2/finishedGameFinalScore;
NSLog(@"interval = %f",interval);

The log returns 0.000000

Is there a limit for decimal places? I need to preserve the decimal result.

Thanks Shani

Answer

Dustin picture Dustin · Aug 15, 2012

The reason your code doesn't work is that you're dividing an integer by another integer and then casting the result to a float.

So you have 2 (an integer) and some other number (also an integer). Then you divide 2 by this number - which is probably greater than 2. Let's say it's 3.

Integer sees 2/3 and he's like "0.66666667? Pshh, no one ever needs anything after the decimal point anyway". So he truncates it. You just have 0.

Then Integer gives the number to Mr. float and Mr float is super happy to get a number! He's all like "yay, a 0! I'm going to add ALL OF THE SIGNIFICANT DIGITS". And that's how you end up with 0.0000000.

So yeah, just cast to a float first. Or even a double!

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