In java, what does double d = 0.0D mean?

I am looking at somebody elses code, and they have:

double d = 0.0D

Whats the huge D for at the end?

as far as I have the ability to tell: double d = 0.0; does the same thing.

simple 10pts

The “D” turns a number into a “double”. But 0.0 is already a double. So the “D” is unnecessary.

The “D” is supposed to be used for quick conversions to double, such as changing an int to a double, like this

double d = 0D;

Java also has “F” and “L” to convert numbers to “float” and “long”.