Question

Max float is defied as:

math.h

#define    MAXFLOAT    0x1.fffffep+127f

I’m a little sad I never noticed this before. What’s this actually say? I would have expected something like this:

#define    MAXFLOAT    0xFFFFFFFF-1

Would that even work?

Answer 1

0x1.fffffep+127 is (roughly)
1.99999999999999999999998 times 2^127. It’s a floating point number, with an exponent, in hexadecimal.

• 0x = hex notation
• 1 = integer part of the number
• .fffffe = fractional part of the number
• p+127 = scientific notation for “times two to the 127th power”