🔴 Hot Update: computer science fundamentals/program to print first even numbers

Given a number n, print the first n positive even numbers in increasing order in a single line using a for loop.

Examples:

Input: n = 2
Output: 2 4
Explanation: The first 2 positive even numbers are 2 and 4.
Input: n = 6
Output: 2 4 6 8 10 12
Explanation: The first 6 positive even numbers are 2, 4, 6, 8, 10 and 12.

The idea is to use a for loop to iterate from 1 to n.
In each iteration, multiply the loop variable by 2 to obtain the next positive even number and print it.
The for loop continues until n even numbers have been printed.

C++

#include <bits/stdc++.h>
using namespace std;

int main() {
    int n = 10;
    // cin >> n;

    // Print the first n positive even numbers in increasing order.
    for (int i = 1; i <= n; i++) {
        cout << 2 * i;

        // Print a space only if more numbers remain.
        if (i < n) {
            cout << " ";
        }
    }

    return 0;
}

#include <stdio.h>

int main() {
    int n = 10;
    // scanf("%d", &n);

    // Print the first n positive even numbers in increasing order.
    for (int i = 1; i <= n; i++) {
        printf("%d", 2 * i);

        // Print a space only if more numbers remain.
        if (i < n) {
            printf(" ");
        }
    }

    return 0;
}

Java

import java.util.Scanner;

class GFG {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        // int n = sc.nextInt();
        
        int n = 10;

        // Print the first n positive even numbers in increasing order.
        for (int i = 1; i <= n; i++) {
            System.out.print(2 * i);

            // Print a space only if more numbers remain.
            if (i < n) {
                System.out.print(" ");
            }
        }

        sc.close();
    }
}

Python

if __name__ == "__main__":
    # n = int(input())
    n = 10

    # Print the first n positive even numbers in increasing order.
    for i in range(1, n + 1):
        print(2 * i, end="")

        # Print a space only if more numbers remain.
        if i < n:
            print(" ", end="")

using System;

class GFG {
    static void Main(string[] args) {
        // int n = Convert.ToInt32(Console.ReadLine());
        
        int n = 10;

        // Print the first n positive even numbers in increasing order.
        for (int i = 1; i <= n; i++) {
            Console.Write(2 * i);

            // Print a space only if more numbers remain.
            if (i < n) {
                Console.Write(" ");
            }
        }
    }
}

JavaScript

// const fs = require('fs');

// const input = fs.readFileSync(0, 'utf8').trim();
// const n = parseInt(input);

let n = 10;

// Print the first n positive even numbers in increasing order.
for (let i = 1; i <= n; i++) {
    process.stdout.write((2 * i).toString());

    // Print a space only if more numbers remain.
    if (i < n) {
        process.stdout.write(" ");
    }
}

Output

2 4 6 8 10 12 14 16 18 20

Print First n Even Numbers Using For Loop

Explore