Difference among Double.MIN_NORMAL and Double.MIN_VALUE

Question

May I know what is the difference among Double.MIN_NORMAL (introduced in 1.6) and Double.MIN_VALUE?

JavaDoc of Double.MIN_NORMAL:

A constant holding the smallest positive normal value of type double, 2^-1022

JavaDoc of Double.MIN_VALUE:

A constant holding the smallest positive nonzero value of type double, 2^-1074

Answer 1

The answer can be found in the IEEE specification of floating point representation:

For the single format, the difference between a normal number and a subnormal number is that the leading bit of the significand (the bit to left of the binary point) of a normal number is 1, whereas the leading bit of the significand of a subnormal number is 0. Single-format subnormal numbers were called single-format denormalized numbers in IEEE Standard 754.

That is, (if I interpret it correctly) Double.MIN_NORMAL is the smallest possible number you can represent, provided that you have a 1 in front of the binary point (what is referred to as decimal point in a decimal system). While Double.MIN_VALUE is basically the smallest number you can represent without this constraint.