“f” after number

Question

What does the f after the numbers indicate? Is this from C or Objective-C? Is there any difference in not adding this to a constant number?

CGRec         


        

Answer 1

Sometimes there is a difference.

float f = 0.3; /* OK, throw away bits to convert 0.3 from double to float */
assert ( f == 0.3 ); /* not OK, f is converted from float to double
   and the value of 0.3 depends on how many bits you use to represent it. */
assert ( f == 0.3f ); /* OK, comparing two floats, although == is finicky. */