What's the strangest corner case you've seen in C# or .NET? [closed]

Answer 1

Few years ago, when working on loyality program, we had an issue with the amount of points given to customers. The issue was related to casting/converting double to int.

In code below:

double d = 13.6;

int i1 = Convert.ToInt32(d);
int i2 = (int)d;

does i1 == i2 ?

It turns out that i1 != i2. Because of different rounding policies in Convert and cast operator the actual values are:

i1 == 14
i2 == 13

It's always better to call Math.Ceiling() or Math.Floor() (or Math.Round with MidpointRounding that meets our requirements)

int i1 = Convert.ToInt32( Math.Ceiling(d) );
int i2 = (int) Math.Ceiling(d);