What does 1.f mean

Question

While going through a class I saw 1.f assigned as a value to a float variable. What is the use of the . here? How is this different from just 1f?

Answer 1

It's exactly the same as 1f and means the number 1.0 expressed as a float literal. Other ways to express the same literal include 1.0f, +1.00000f, 1e0f, 1.e+0f and so on.

For a detailed specification, see §3.10.2. Floating-Point Literals in the JLS.