Why is an integer literal followed by a dot a valid numeric literal in JavaScript?

In JavaScript it is valid to end an integer numeric literal with a dot, like so...

x = 5.;

What's the point of having this notation? Is there any reason to put the dot at the end, and if not, why is that notation allowed in the first place?

Update: Ok guys, since you mention floats and integers... We are talking about JavaScript here. There is only one number type in JavaScript which is IEEE-754.

5 and 5. have the same value, there is no difference between those two values.