Question

I want to convert a floating point user input into its integer equivalent. I could do this by accepting an input string, say “-1.234” and then I could just explicitly convert each character to it’s decimal representation. (big endian by the way). So I would just say for the example I gave,

-1.234 = 1|01111111|00111011111001110110110

sign bit = 1 = 128<<31
exponent bits = 01111111 = 127<<23
mantissa bits = 00111011111001110110110 = 1962934
decimal equivalent = 1962934 + 127<<23 + 128<<31

This is easy enough but unwieldy. Is there a better way to do this? Maybe some sort of type casting I can do?

Answer 1

float a = -1.234;
int b = *(int*)&a;

Also, in C++ there’s this conversion operator that doesn’t do any checks, reinterpret_cast. It’s probably better here.

int b = *reinterpret_cast<int*>(&a);