MAXFLOAT in Objective-C

Question

The maximum float value is ignored as:

math.h

#define    MAXFLOAT    0x1.fffffep+127f

I'm a little sad that I had not noticed this before. What does this actually say? I would expect something like this:

#define    MAXFLOAT    0xFFFFFFFF-1

Will this work?

Answer 1

0x1.fffffep+127 (approximately) 1.9999999999999999999999998 times 2 ^ 127. This is a floating point number with an index in hexadecimal format.

• 0x= hexadecimal notation
• 1= integer part of a number
• .fffffe= fractional part of a number
• p+127= scientific notation for “from two to 127th degree”

Answer 2

MAXFLOAT required for UNIX compliance:

MAXFLOAT

     

[XSI] The value of the maximum number of infinite single-precision floating-point numbers.

0x1.fffffep+127f - , C .

C , FLT_MAX <float.h>, ( " ", § 5.2.4.2.2). FLT_MAX - , .