Floating-Point Numbers and Type double

Floating-point number

• A number with a decimal point, such as 7.33, 0.0975 or 1000.12345.
• float and double primitive types
• double variables can store numbers with larger magnitude and finer detail than float variables

float represents single-precision floating-point numbers up to seven significant digits.

double represents double-precision floating-point numbers that require twice as much memory as float and provide 15 significant digits—approximately double the precision of float variables.

Java treats all floating-point literals (such as 7.33 and 0.0975) as double values by default.

Appendix D, Primitive Types shows the ranges of values for floats and doubles