%X format specifier prints value only up to 4 bytes?

Question

Hex value of 6378624653 is : 0x17C32168D But this code prints : 0x7C32168D

#include<iostream>

int main()
{
    int x = 6378624653;
    printf("0x%x", x);
}

can anyone explain why this happens ? and what should I do to get the right output?

Answer 1

The obtained result means that an object of the type int can not store such a big value as 6378624653.

Try the following test program.

#include <iostream>
#include <limits>

int main() 
{
    std::cout << std::numeric_limits<int>::max() << '\n';
    std::cout << 6378624653 << '\n';
    std::cout << std::numeric_limits<unsigned int>::max() << '\n';
}

and see what the maximum value that can be stored in an object of the type int. In most cases using different compilers you will get the following output

2147483647
6378624653
4294967295

That is even objects of the type unsigned int can not store such value as 6378624653.

You should declare the variable x as having the type unsigned long long int.

Here is a demonstration program.

#include <cstdio>

int main() 
{
    unsigned long long int x = 6378624653;
    printf( "%#llx\n", x );
}

The program output is

0x17c32168d