C++ Program to Print All Natural Numbers from 1 to N in Iterative Methods

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).

Page content(s):

1. Program & Output

Additional content(s):

1. Algorithm

2. Pseudocode

3. Time Complexity

4. Flowchart

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