Question

Suppose we have

float x = 24.0;

I want to do the following:

// hexRepresentation is of format HxHHHHHHHH 
// where H is a hexadecimal symbol 0-9 or a-f
NSString *hexRepresentation = [self hexadecimalFromFloat:x];

Please help me complete the following method:

- (NSString *)hexadecimalFromFloat:(float)flt {
    NSString *h;
    /*
        What should I do here to convert the float
        value into its HxHHHHHHHH format? Then what
        should I do to ensure it's converted into a
        proper NSString and assigned to h?
     */
    return h;
}

Answer 1

Rough, untested code:

unsigned int *fp = (unsigned int*)&flt;
h = [NSString stringWithFormat:@"0x%08X", *fp];

This may or may not be in IEEE-754 notation, etc etc. It also assumes sizeof(float) == sizeof(int) == 4