the output is attached hereAs a teacher had assigned us to find the sum of N even numbers using while loop,the code executes but does not give a proper sum.Can anyone tell me where am i going wrong??

#include <iostream>
using namespace std;
int
main ()
{
  int i, n, z, sum;
  i = 1;
  cout << "enter the number till which even numbers are to be displayed:";
  cin >> n;
  cout << "the first " << n << " even numbers are:" << endl;

  while (i <= n)
    {
      z = i   * 2;
      cout << " " << z << endl;
      sum  = z;

    }

  cout << "the sum is :" << sum;
  return 0;


}

CodePudding user response：

From your output, it's clear that you haven't initialized sum before using it. Add this line:

sum = 0;

somewhere before the loop and it'll all work out fine.

CodePudding user response：

using namespace std;
int
main ()
{
  int i, n, z, sum=0;
  i = 1;
  cout << "enter the number till which even numbers are to be displayed:";
  cin >> n;
  cout << "the first " << n << " even numbers are:" << endl;

  while (i <= n)
    {
      Z=i  *2;
      cout << " " << z << endl;
      sum  = z;

    }

  cout << "the sum is :" << sum;
  return 0;


}```

CodePudding user response：

It is because you haven't initialized sum in variable declaration. So by default sum will take garbage value.

So you have to initialize sum variable with 0.

int sum = 0;
int i,n,z;