convert 64 bit decimal to binary

Question

I want to convert double num to binary, but mantissa does not work and I dunno why, here is the code... please do not use other libs (only stdio)

 void printBinary(int n, int i)
{
    int k;
    for (k = i - 1; k >= 0; k--) {

        if ((n >> k) & 1)
            printf("1");
        else
            printf("0");
    }
}
typedef union {
    double f;
    struct
    {
        unsigned long long mantissa : 52;
        unsigned long long exponent : 11;
        unsigned long long sign : 1;

    } raw;
} myDouble;
void printIEEE(myDouble var)
{
    printf("%d |", var.raw.sign);
    printBinary(var.raw.exponent, 11);
    printf(" | ");
    printBinary(var.raw.mantissa, 52);
    printf("\n");
}

then I do in main

myDouble var;
var.f = -8.34;
printf("IEEE 754 representation of %f is : \n",
        var.f);
    printIEEE(var);

Answer 1

Your binary print function is

void printBinary(int n, int i)

but you are passing unsigned long long values. Please change the function to

void printBinary(unsigned long long n, int i)