问题
Possible Duplicate:
What is the behavior of integer division in C?
When I do a division calculation with an answer that's supposed to be between 1 and 0, it always returns 0.
Try this:
float a = 1;
float b = 2;
float c = a / b; //variable divide by variable gives 0.5 as it should
float d = 1 / 2; //number divide by number gives 0
float e = 4 / 2;
NSLog(@"%f %f %f %f %f", a,b,c, d, e);
I get this from the console:
2013-01-17 14:24:17.512 MyProject[1798:c07] 1.000000 2.000000 0.500000 0.000000 0.500000
I have no idea what is going on.
回答1:
You're dividing integer with integer. The result will be an integer, the remainder is omitted:
1 / 2 = 0 The remainder (0.5) is omitted.
Only after the division is done, your result is passed into your float d variable.
EDIT: Right, I forgot to suggest a solution: Make sure at least one of your operands is a float.
1.0 / 2 = 0.5
1 / 2.0 = 0.5
来源：https://stackoverflow.com/questions/14370857/division-with-expected-result-between-1-and-0-always-gives-0