ThreadWay3.java

public class ThreadWay3 {

    public static class Counter {
        int count;

        public synchronized void increment() {
            count++;
        }
    }

    public static void main(String[] args) {
        Counter counter = new Counter(); 
        Runnable obj1 = () -> {
            for (int i = 0; i < 1000; i++) {
                counter.increment();
            }
        };
        
        Runnable obj2 = () -> {
            for (int i = 0; i < 1000; i++) {
                counter.increment();
            }
        };

        Thread t1 = new Thread(obj1);
        Thread t2 = new Thread(obj2);

        t1.start();
        t2.start();

        try {
            t1.join();
            t2.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println(counter.count);
    }
}