take a look on this code

Question

#include <iostream>
using namespace std;

int main()
{

int a=1;
int b=3;
int sum = a + b;

cout << sum,"\nhello world";

return 0;
}

it prints 4 not
4
hello world

Answer 1

put << between sum and text

Answer 2

Taste the comma is an operator used to separate statements/expressions. There are two statements:
cout << sum
and:
"\nhello world"
with the comma between them. The second doesn't have any effect as the result wasn't stored.

Answer 3

replace , with <<
i'm not sure whats going on here i thought it wont compile or runtime exception thrown, but its not.

Answer 4

thanks for cooperation