C++ program to print all the natural numbers from 1 to N can be written in both iterative and recursive methods. In the iterative method, the task can be performed by using for loop, while loop and do-while loop. Here, all the C++ programs using different loops have been covered to print the natural numbers from 1 to N (1, 2, 3, ..., N).

## 1. C++ Program & output to Print First N Natural Numbers

Code has been copied
/************************************
alphabetacoder.com
C++ program to print all natual
numbers from 1 to n  using for loop
**************************************/

#include <iostream>

using namespace std;

int main() {
// declare variables
int n, i;

//take input of the number upto which
// natural numbers will be printed
cout << "Enter the upper limit = ";
cin >> n;

// iterate from 1 to n and print the number
cout << "First " << n << " natural numbers are : ";
for (i = 1; i <= n; i++)
cout << i << " ";
return 0;
}


Output

#### Case 1:

Enter the upper limit = 10

First 10 natural numbers are : 1 2 3 4 5 6 7 8 9 10

#### Case 2:

Enter the upper limit = 5

First 5 natural numbers are : 1 2 3 4 5

/**************************************
alphabetacoder.com
C++ program to print all natual
numbers from 1 to n  using while loop
***************************************/

#include <iostream>

using namespace std;

int main() {
// declare variables
int n, i;

//take input of the number upto which
// natural numbers will be printed
cout << "Enter the upper limit = ";
cin >> n;

// iterate from 1 to n and print the number
cout << "First " << n << " natural numbers are : ";
i = 1;
while (i <= n) {
cout << i << " ";
i++;
}
return 0;
}


Output

#### Case 1:

Enter the upper limit = 10

First 10 natural numbers are : 1 2 3 4 5 6 7 8 9 10

#### Case 2:

Enter the upper limit = 5

First 5 natural numbers are : 1 2 3 4 5

/*****************************************
alphabetacoder.com
C++ program to print all natual numbers
from 1 to n  using do - while loop
******************************************/

#include <iostream>

using namespace std;

int main() {
// declare variables
int n, i;

//take input of the number upto which
// natural numbers will be printed
cout << "Enter the upper limit = ";
cin >> n;

// iterate from 1 to n and print the number
cout << "First " << n << " natural numbers are : ";
i = 1;
do {
cout << i << " ";
i++;
} while (i <= n);

return 0;
}


Output

#### Case 1:

Enter the upper limit = 10

First 10 natural numbers are : 1 2 3 4 5 6 7 8 9 10

#### Case 2:

Enter the upper limit = 5

First 5 natural numbers are : 1 2 3 4 5