Why answer is " sum= 21"

Question

#include <iostream>
using namespace std;

int main()
{
int array [7],sum=0;
for(int i=0;i<7;i++)
{
array [i] = i;
sum +=array[i];
}
cout << "sum =" << sum;
}

Answer 1

To explain this, look at the 'for' loop.
In short, it means that 'i' , as well as number of arrays will become 0, then 1, then 2, then 3... and it stops once 'i' becomes 7.
And you can see this 'sum += array[i];' , to simplify it, it just means this :
sum = sum + i;

Hence, if you go through the loop until 'i' becomes 7, sum will become " 0+1+2+3+4+5+6" which is 21.

Answer 2

sum initially is 0.
in the 'for loop' we add each i value to sum until i=6 (i<7).
that makes
0+1+2+....+6 = which is nothing but 21.

Answer 3

can any body explain the code

Answer 4

i can

Answer 5

please tell me why the answer sum = 21

Answer 6

thank you to explain