Implicit conversion of integers to floats in c

Question

I'm having trouble understading why this code's output is 2147483648:

#include <stdio.h>
int main (void){
    float f = 2147483638;
    printf("%f",f);
}

I tried to find explanation using IEEE 754 standard for float representation but using my calculations I get that output should be 2147483520, not 2147483648. Thanks for help!

Answer 1

That is the way that float works on your system.

Note that the C standard is intentionally flexible as to the type and sizes of the floating point types. A float does not have to be an IEEE754 32 bit floating point type.