Easy math function with int64_t not working

Question

Possible Duplicate:
how do you divide two integers and get a decimal answer?

This is probably really easy but I can't find the solution. I'm not a "real" programmer...

I'm storing number and scores on my app using int_64.

 .h

 int64_t score;

 @property (nonatomic, assign) int64_t score;

.m

 @synthesize score;

Here is the math:

self.score = 7/3;

The result is "2", instead of "2.33333...". I should use use something different from int_64, but what?

I wanted the result to be "2,33", with two digits after the comma. Can anyone help? Thanks!

also http://stackoverflow.com/questions/5543661/whats-wrong-with-this-division — rob mayoff, Nov 25 '12 at 22:50
also http://stackoverflow.com/questions/8459351/objective-c-division-of-two-ints — rob mayoff, Nov 25 '12 at 22:51
also http://stackoverflow.com/questions/12857438/division-result-is-not-correct — rob mayoff, Nov 25 '12 at 22:53

Joni · Accepted Answer · 2012-11-25T22:57:44.527

2

int stores whole numbers, also called integers. For calculations with a fractional part use double.

Also, it's better to fix the number of digits is when formatting for display. For example:

double score = 7.0/3.0;
NSString *strScore = [NSString stringWithFormat:@"%.2f", score];

edited Nov 25 '12 at 22:57

answered Nov 25 '12 at 22:51

Joni

Tim · Answer 2 · 2012-11-25T22:46:02.157

1

You should use double to store decimal numbers instead of int. If you try to store a decimal number in an int it will get rounded.

@property (nonatomic, assign) double score;

edited Nov 25 '12 at 22:46

answered Nov 25 '12 at 22:40

Tim

Thx, but this is giving me the answer "2.000000". – tomDev Nov 25 '12 at 22:45
1

This only fixes half of the issue. The integer division is still done because both operands are integers. – rmaddy Nov 25 '12 at 22:49
You can find how to limit a double to 2 decimals here http://stackoverflow.com/questions/1113408/limit-a-double-to-two-decimal-places – Tim Nov 25 '12 at 22:51

2 Answers2