Example to create a new thread and run it class ThreadDemo extends Thread { private Thread t; private String threadName;

ThreadDemo(String name) { threadName = name; System.out.println("Creating " + threadName ); }

public void run() { System.out.println("Running " + threadName );

  try {

     for(int i = 4; i > 0; i--) {
        System.out.println("Thread: " + threadName + ", " + i);
       // Let the thread sleep for a while.
        Thread.sleep(50);
     }
  } catch (InterruptedException e) {
     System.out.println("Thread " +  threadName + " interrupted.");
  }
  System.out.println("Thread " +  threadName + " exiting.");

}

public void start () { System.out.println("Starting " + threadName );

  if (t == null) {
     t = new Thread (this, threadName);
     t.start ();
  }

} }

public class TestThread1{

public static void main(String args[]) { ThreadDemo T1 = new ThreadDemo("Thread-1"); T1.start();

  ThreadDemo T2 = new ThreadDemo("Thread-2");
  T2.start();

}
}

class ThreadOps implements Runnable { public Thread t; private String threadName; boolean suspended = false;

ThreadOps(String name) { threadName = name; System.out.println("Creating " + threadName ); }

public void run() { System.out.println("Running " + threadName );

  try {

     for(int i = 10; i > 0; i--) {
        System.out.println("Thread: " + threadName + ", " + i);

        // Let the thread sleep for a while.
        Thread.sleep(300);

        synchronized(this) {

           while(suspended) {
              wait();
           }
        }
     }
  } catch (InterruptedException e) {
     System.out.println("Thread " +  threadName + " interrupted.");
  }
  System.out.println("Thread " +  threadName + " exiting.");

}

public void start () { System.out.println("Starting " + threadName );

  if (t == null) {
     t = new Thread (this, threadName);
     t.start ();
  }

}

void suspend() { suspended = true; }

synchronized void resume() { suspended = false; notify(); } }

public class OpsTst {

public static void main(String args[]) { ThreadOps R1 = new ThreadOps("Thread-1"); R1.start();

  ThreadOps R2 = new ThreadOps("Thread-2");
  R2.start();

  try {
     Thread.sleep(1000);
     R1.suspend();
     System.out.println("Suspending First Thread");
     Thread.sleep(1000);
     R1.resume();
     System.out.println("Resuming First Thread");

     R2.suspend();
     System.out.println("Suspending thread Two");
     Thread.sleep(1000);
     R2.resume();
     System.out.println("Resuming thread Two");
  } catch (InterruptedException e) {
     System.out.println("Main thread Interrupted");
  } try {
     System.out.println("Waiting for threads to finish.");
     R1.t.join();
     R2.t.join();
  } catch (InterruptedException e) {
     System.out.println("Main thread Interrupted");
  }
  System.out.println("Main thread exiting.");

} }

scala higher1 { def math(x: Double, y:Double, fn: (Double,Double)=>Double): Double = fn(x,y);
def main(args:Array[String]) { val result = math(50,20,(x,y)=>x max y); println(result); } }

object higher2 { def math(x: Double, y:Double, z:Double, fn: (Double,Double)=>Double): Double = fn(fn(x,y),z);
def main(args:Array[String]) { val result = math(50,20,10,(x,y)=>x * y); println(result); } }

object curry { def add(x:Int,y:Int) = x + y def add2(x:Int) = (y:Int) => x + y; //curried version def add3(x:Int)(y:Int) = x + y; //Simpler scala version def main(args:Array[String]) { println(add(20,10)); println(add2(20)(10)); //calling curried add2 val sum40 = add2(40); println(sum40(100)); //Partial application println(add3(100)(200)); //calling simpler scala version val sum50 = add3(50)_; //partial application of simple version println(sum50(400)); } }

object myreduce {

val lst = List(1,2,3,5,7,10,13); val lst2 = List("A","B","C"); def main(args:Array[String]) { println(lst.reduceLeft(_+_)); //adds all the elements of lst
println(lst.reduceLeft((x,y)=>{println(x + "," + y);x+y;}))
println(lst2.reduceLeft(_+_)); //concatenates lst2 println(lst.reduceRight(_+_)); //adds all the elements of lst println(lst.reduceLeft(_-_)); //subtract using reduceRight println(lst.reduceRight(_-_)); //subtract using reduceRight println(lst.reduceLeft((x,y)=>{println(x + "," + y);x-y;})) println(lst.reduceRight((x,y)=>{println(x + "," + y);x-y;})) } }