C# Math division not correct

Question

Possible Duplicate:
Division returns zero
simple calculation not working for some reason

Why is this:

int prozent = (totalkcals / 2000) * 100;

returning 0?

totalkcals is in this case 567, I double-checked it.

score 6 · Answer 1 · answered Sep 11 '12 at 14:37

This is because of integer division

The division rounds the result towards zero, and the absolute value of the result is the largest possible integer that is less than the absolute value of the quotient of the two operands. The result is zero or positive when the two operands have the same sign and zero or negative when the two operands have opposite signs

score 3 · Answer 2 · answered Sep 11 '12 at 14:38

3

Its because of Integer division.

double prozent = ((double)totalkcals / 2000) * 100;

answered Sep 11 '12 at 14:38

Roshana

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score 2 · Answer 3 · answered Sep 11 '12 at 14:39

2

567 / 2000 = 0.2835, which when cast to an int (as specified by your data type) becomes zero. 0 * 100 = 0.

So: double prozent = ((double)totalcals / 2000.0) * 100.0;

answered Sep 11 '12 at 14:39

Sam Axe

33,313
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score 1 · Answer 4 · answered Sep 11 '12 at 14:38

1

Its because its an integer calculation, so the operation from (totalkcals / 2000) returns 0;

answered Sep 11 '12 at 14:38

Freeman

5,691
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C# Math division not correct

4 Answers4