double rats = 8912D ;

Scientific Notation

Either of the following also works:

double rats = 8912 ;

or

double rats = 8912.0 ;

The first statement (above) works, but is "sloppy" coding. The integer literal must be converted into a double before the variable is initialized. In the second statement the variable is initialized to the double literal.

You will sometimes see scientific notation. The following are all double-precision literals:

1.23E+02     -1.235E+02      -1.98234234E+05    3.81E-06

The big "E" means "times 10 to the power of" . The integer that follows it says what power of ten to multiply the rest of the number by.  

Another way of regarding the integer that follows the "E" is that it says in which direction and for how many places to shift the decimal point. Positive integers mean right shifts; negative integers mean left shifts.