Introduction

In this lesson, we will expand our understanding of Java by exploring how to identify and generate the first N even numbers, N odd numbers, and N prime numbers. These practical applications will enhance your programming skills by leveraging loops, conditionals, and algorithms in Java.

Defining Even Numbers in Java

An even number is defined as any integer that is divisible by 2, which means the remainder when divided by 2 is zero. In Java, we can easily identify even numbers using the modulus operator %. Here’s a simple method to check if a number is even:

public class EvenNumberChecker {
    public static boolean isEven(int number) {
        return number % 2 == 0;
    }
}

Example: Generate First N Even Numbers

To generate the first N even numbers, we can use a for loop:

public class FirstNEvenNumbers {
    public static void main(String[] args) {
        int N = 10; // Specify how many even numbers to generate
        System.out.println("First " + N + " Even Numbers:");
        for (int i = 0; i < N; i++) {
            System.out.print(i * 2 + " ");
        }
    }
}

Output:

First 10 Even Numbers:
0 2 4 6 8 10 12 14 16 18 

This program utilizes a for loop to iterate from 0 to N-1, multiplying the loop variable by 2 to produce the first N even numbers.