Double data type never get accurate result

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

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

However,

x =120.0;
y = 0.5;
double z= x % y;

did indeed gave the correct result of 0.

Accuracy problems

Solution:  

Since Decimal types are perfectly accurate and float’s are not, why would we still want to use the intrinsic float/double types? Short answer – performance. In my speed tests Decimal types ran over 20 times slower than their float counterparts.

So if you’re writing a financial application for a bank that has to be 100% accurate and performance is not a consideration, use the Decimal type. On the other hand, if you need performance and extremely small floating point variations don’t affect your program, stick with the float and double types.