How do you compare floating point numbers?

Question

Using fprintf() print a single floating point number right-justified in a field of 20 spaces, no leading zeros, and 4 decimal places. The destination should be stderr and the variable is called num.

Answer 1

int compareFloats(float f1, float f2)
{
    char *b1, *b2; 
            int i; 

    b1 = (char *)&f1; 
    b2 = (char *)&f2; 

    /* Assuming sizeof(float) is 4 bytes) */ 

     for (i = 0; i < 4; i++, b1++, b2++) 
    {
        if (*b1 != *b2) 
        {
            return(NOT_EQUAL); /* You must have defined this before */ 
        }
    }

    return(EQUAL);
}

Answer 2

You can easily compare floats or any other data types variable by using memcmp() .

int float_cmp(float *f1, float *f2)
{
        return memcmp((void *)f1, (void *)f2, sizeof(float));
}