Comma operator
#include <iostream>
using namespace std;
int main()
{
int i, j;
j = 10;
i = (j++, j+100, 999+j);
cout << i;
return 0;
}1010
Demonstrating the comma operator
#include <iostream>
#include <iomanip>
using std::cout;
using std::cin;
using std::endl;
using std::setw;
int main() {
int count = 10;
for(long n = 1, sum = 0, factorial = 1;sum += n, factorial *= n, n <= count ;
n++)
cout << setw(4) << n << " "
<< setw(7) << sum << " "
<< setw(15) << factorial
<< endl;
return 0;
}1 1 1
2 3 2
3 6 6
4 10 24
5 15 120
6 21 720
7 28 5040
8 36 40320
9 45 362880
10 55 3628800
The Comma Operator: The value of a series of expressions is the value of the right most
#include <iostream>
using namespace std;
int main()
{
long num1 = 0, num2 = 0, num3 = 0, num4 = 0;
num4 = (num1 = 10, num2 = 20, num3 = 30);
cout << num4;
cout << endl;
return 0;
}