Why do I see a double variable initialized to some value like 21.4 as 21.399999618530273?

Question

double r = 11.631;
double theta = 21.4;

In the debugger, these are shown as 11.631000000000000

Answer 1

One way you can avoid this is to use a library that uses an alternative method of representing decimal numbers, such as BCD

Answer 2

If it bothers you, you can customize the way some values are displayed during debug. Use it with care :-)

Enhancing Debugging with the Debugger Display Attributes