Below code gives output as 8. How it is possible?

Question

#include <iostream>
using namespace std;
int main()
{
int a=010;
cout<<a;
return 0;
}
// Output: 8

Answer 1

@Arjun Gowda
The support for 0b was added only after C++03, so if you use an older compiler, 0b may just return an error.

Answer 2

what about this?

#include <iostream>
using namespace std;
int main()
{
int a=0b111;
cout<<a;
return 0;
}
//Output 7

Answer 3

ok what is the prefix for hexadecimal?