output

[andersonlam]

i want to ask how to copy one of outputs in while loop to display outside the loop

 #include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;
int main()
{
 int iter, m, n=0, it = -1 , cnt =0;

 double sum  , pi1 = sqrt(12), rt =0;

 cout <<"This program estimates the value of PI using the Babylonian method.\n\n";
 cout <<"Enter a count that will be used for series iteration: ";
 cin >> iter; cout <<"\n";
 cout << fixed <<setprecision(14);
 if (iter == 0)
 {
     cout <<"The input count must be greater than 0.\n";
     cout <<"Try entering again: ";
     cin>>iter;
     cout <<"\n";
 }

 while ((n - iter)<=-1 )
 {
   it *= -1;
   ++cnt;
   m = 3 + (2*(n-1));
   sum = it / (m * pow(3,n));
   rt += sum;
   ++n;

   cout << setw(2)<<cnt <<"    "<< pi1 * rt<<endl;

 }

    return 0;
}

as you can see if i enter 10 in cin >> iter . the output will be like
1 ....
2 ....
3 ....
4 ....
5 ....
6 ....
7 ....
8 ....
9 ....
10 ....
but the last line of the program i want to write a code line to display the last output of the loop so it can be like this:
1 ....
2 ....
3 ....
4 ....
5 ....
6 ....
7 ....
8 ....
9 ....
10 ....

the last output is ...... // the .... is the result belongs to the 10th line (which means the last line ).

[Hengry]

You can do something like

if(cnt == iter){
cout << "Last output is" << setw(2)<<cnt <<"    "<< pi1 * rt<<endl;
}

[Enoizat]

If you want a value created inside a loop to be printed after the loop ending, you need to save it inside a variable created before the loop start:

#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;
int main()
{
    int iter, m, n=0, it = -1 , cnt =0;

    double sum  , pi1 = sqrt(12), rt =0;

    cout <<"This program estimates the value of PI using the Babylonian method.\n\n";
    cout <<"Enter a count that will be used for series iteration: ";
    cin >> iter; cout <<"\n";
    cout << fixed <<setprecision(14);
    if (iter == 0)
    {
        cout <<"The input count must be greater than 0.\n";
        cout <<"Try entering again: ";
        cin>>iter;
        cout <<"\n";
    }

    double lastsaved = 0; // declare a variable outside the loop <----//
    while ((n - iter)<=-1 )                                           //
    {                                                                 //
        it *= -1;                                                     //
        ++cnt;                                                        //
        m = 3 + (2*(n-1));                                            //
        sum = it / (m * pow(3,n));                                    //
        rt += sum;                                                    //
        ++n;                                                          //
                                                                      //
        lastsaved = pi1 * rt; // then update it inside the loop <-----//
        cout << setw(2) << cnt << "    " << lastsaved << endl;
    }
    std::cout << "the last output is " << lastsaved << '\n';

    return 0;
}