AlternateNumbers.java

// Write a Java program to Print alternate numbers using 2 Threads.

class Numbers {
    int n = 0;
    int end;

    Numbers(int end) {
        this.end = end;
    }

    synchronized void printEvenNum() {
        while (n <= end) {
            if (n % 2 == 0) {
                System.out.println(Thread.currentThread().getName() + " is printing " + n);
                n++;
                notify();
            } else if (n % 2 != 0) {
                try {
                    wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    synchronized void printOddNum() {
        while (n <= end) {
            if (n % 2 != 0) {
                System.out.println(Thread.currentThread().getName() + " is printing " + n);
                n++;
                notify();
            } else if (n % 2 == 0) {
                try {
                    wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

public class AlternateNumbers {
    public static void main(String[] args) {
        final Numbers num = new Numbers(100);

        new Thread() {
            public void run() {
                num.printEvenNum();
            }
        }.start();
        new Thread() {
            public void run() {
                num.printOddNum();
            }
        }.start();
    }
}