I've seen several examples in books and around the web where they sometimes use decimal places when declaring float values even if they are whole numbers, and sometimes using an "f" suffix. Is this necessary?

For example:

[UIColor colorWithRed:0.8 green:0.914 blue:0.9 alpha:1.00];

How is this different from:

[UIColor colorWithRed:0.8f green:0.914f blue:0.9f alpha:1.00f];

Does the trailing "f" mean anything special?

Getting rid of the trailing zeros for the alpha value works too, so it becomes:

[UIColor colorWithRed:0.8 green:0.914 blue:0.9 alpha:1];

So are the decimal zeros just there to remind myself and others that the value is a float?

Just one of those things that has puzzled me so any clarification is welcome :)