Output inside outer loop , innerloop and in main I need a good explanation of the outputs and why??

Question

#include <iostream>
using namespace std;

int main() {
int i;
for(i = 0; i < 4; ++i){
for(int j = 0; j < 4; ++j){
i = i + j;

cout<<i;
//0136
}

//cout<<i;
//6
}
//cout<<i;
//7
return 0;
}

Answer 1

Inside for (int j = 0; j < 4; j++)
First iteration:
i = 0 + 0 -> output 0
Second
i = 0 + 1 -> output 1
Third
i = 1 + 2 -> output 3
Fourth
i = 3 + 3 -> output 6
The loop exit and then execute cout << i inside the other loop, which will print the same value of i, 6. After the execution, i is incramented and then the loop exit because the value of i is now 7, 7 < 4 (false). After that, cout << i in the main scope is executed