C++ Program to Print Prime Numbers from 1 to N using For loop

C++ program to print prime numbers from 1 to N using for loop of any range.

In this article, you will learn how to print prime numbers between 1 to N using for loop.

Example

Sample of Prime Numbers

You should have knowledge of the following topics in c++ programming to understand these programs:

• C++ main() function
• C++ for loop
• C++ while loop

Source Code

// C++ Program to Print Prime Numbers from 1 to N using For loop
#include <iostream>
using namespace std;

int main() {
    int x, i, j, f;
    
    cout << "Enter the range number to print the prime numbers:\n";
    cin >> x;
    
    cout << "\n\nThe prime numbers between 1 and " << x << " are:\n\n";
 
    for (i = 1; i <= x; i++) {
        
        // They are niether prime nor composite if as skip 0 and 1
        if (i == 1 || i == 0) {
            continue;
        }
        
        f = 1;
 
        for (j = 2; j <= i / 2; ++j) {
            if (i % j == 0) {
                f = 0;
                break;
            }
        }
 
        // f = 1 means i is prime and f = 0 means i is not prime
        if (f == 1) {
            cout << " " << i;
        }
    }
    return 0;
}

Run

Output

Explanation

In this given program, we have taken input 100 from the user via the system console then we applied the standard formula to print the prime numbers.

After the whole calculation, It will return the 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 the output of the above program.