Exception to Number Format Exception with “D” and “F”?

Question

I have run into a very strange problem in my code. I have a simple temperature converter where the user enters the temperature in Celsius and, after pressing \"Convert\", th

Answer 1

some languages allow you to put letters after number literals to signify what type it is.

if you simply wrote 12.3, it might not know whether it is a float or a double(or it'd have to infer or cast it).

Your number parser must be picking up on these letters.

• 12.3d is 12.3 as a double
• 12.3f is 12.3 as a float

Answer 2

Java interprets numbers like 123f as referring to a float and 123d as a double, whereas plain 123 means an int.

Answer 3

Read the documentation on the number format supported by parseDouble. The f and d are instances of FloatTypeSuffix.