Whats different between two values [duplicate]

Question

This question already has an answer here:

Using iPhone/Objective C CGFloats: Is 0.1 okay, or should it be 0.1f? (1 answer)

Closed 7 years ago.

What's different between:

CGFloat gray[4] = {0.9f, 0.9f, 0.9f, 1.0f};

and

CGFloat gray[4] = {0.9, 0.9, 0.9, 1.0};

?

I think they are the same but I don't know for sure.

Answer 1

I believe it is indicating that the number is a float (i.e. single-precision floating point) as opposed to a double (double-precision floating point),