MultiThreading 1

import java.util.*;

class A{
    // im here to just chill
    int counter=0;

    // synchronized : to make a method accessible to single thread at a time
    public synchronized void increaseCounter(){
        counter++;
    }
}

class ThreadViaClass extends Thread{

    String output;

    ThreadViaClass(String output){
        this.output = output;
    }
    // necessary function
    public void run(){
        for(int i=0;i<10;i++){
            System.out.println(this.output);

            // as sleep can throw exception
            try{
                Thread.sleep(500);
            }
            catch(Exception e){
                System.out.println(e);
            }


        }
    }
}

// as there is no multiple inheritance in java :(
class ThreadViaInterface extends A implements Runnable{
    String output;

    ThreadViaInterface(String output){
        this.output = output;
    }

    public void run(){
        for(int i=0;i<10;i++){
            System.out.println(this.output);

            try{
                Thread.sleep(500);
            }
            catch(Exception e){
                System.out.println(e);
            }
        }
    }
}

public class Main{
    // as Thread.join() throws an exception
    public static void main(String args[]) throws Exception{
        Thread t1 = new ThreadViaClass("t1");
        Thread t2 = new ThreadViaClass("t2");

        Thread t3 = new Thread(new ThreadViaInterface("t3"));

        // anonymous class with thread name Thread t4
        Thread t4 = new Thread(() ->
            {
                for(int i=0;i<10;i++){
                    System.out.println("t4");
                    try{
                        Thread.sleep(100);
                    }catch(Exception e){
                        System.out.println(e);
                    }
               }
            }, "Thread t4"
        );

        // setting and getting name for easier access
        t1.setName("thread t1");
        System.out.println(t1.getName());

        // priorities by default 5, 1- lowest 10-highest
        t1.setPriority(10);
        System.out.println(t1.getPriority());
        System.out.println(t2.getPriority());

        // Thread.currentThread(); prints main
        System.out.println(Thread.currentThread().getName());

        // start automatically calls Thread.run();
        t1.start();
        t2.start();
        t3.start();
        t4.start();
        // t1 t2 t3 printed in any order as they are running parallely

        // isAlive()
        System.out.println(t1.isAlive());

        // joining t1 t2 t3 with parent thread (here main)
        t1.join();
        t2.join();
        t3.join();
        t4.join();

        // this prints false
        System.out.println(t1.isAlive());
        // printed at last
        System.out.println("Joined with main thread");
    }
}