Why is modulus operator not working for double in c#?

Question

Consider this:

double x,y;
x =120.0;
y = 0.05;

double z= x % y;

I tried this and expected the result to be 0, but it came out 0.04933333.<

Answer 1

http://en.wikipedia.org/wiki/Floating_point#Accuracy_problems can help you understand why you get these "strange" results. There's a particular precision that floating point numbers can have. Just try these queries and have a look at the results:

0.5 in base 2

0.05 in base 2