RD Programming Concepts Training - Batch 1

FindGCF.java

/*
@Program name: FindGFC.java

Find the greatest common factor using Euclid's algorithm

*/
	
class FindGCF {

	public static void main(String[] args) {
		
		int smallno = 12;
		int bigno = 15;
		int rem = 0;
		
		while((rem = bigno % smallno) != 0) {
			bigno = smallno;
			smallno = rem;
		}
		
		if (smallno == 1) {
			System.out.println("No GCF was found");
		}
		else {
			System.out.println("GCF of " + bigno + " and " + smallno + " is " + smallno);
		}
	}
}

HelloWorld.java

class HelloWorld {
	public static void main(String[] args) {
		System.out.println("Hello World\n");
	}
}

KeyboardInput.java

/*
@Program name: KeyboardInput.java

	Simple routine to accept input from keyboard

*/

import java.io.IOException;

class KeyboardInput {

	final int NUMOFCHARS = 10; // number of characters to accept

	String getInput(String prompt) {
		
		String returnValue = "";
		
		byte b[] =  new byte[NUMOFCHARS];
		System.out.print(prompt + " :__________\b\b\b\b\b\b\b\b\b\b");
		
		try {
			System.in.read(b);
		}
		catch(IOException ioe) {
			ioe.printStackTrace();
		}
		finally {
			returnValue = new String(b);
			return returnValue;
		}
	}

	void tryItOut() {
		String name = getInput("What is your name? ");
		String day = getInput(" what day is it? ");
		
		System.out.print("Hi " + name + " have a nice " + day + " morning\n");
	}

	public static void main(String[] args) {
		new KeyboardInput().tryItOut();
	}

} 

MainParams.java

/*
@program name: MainParams.java

Just print out all the parameters passed from the command line

*/

class MainParams {

	public static void main(String[] args) {
		
		if(args.length == 0) System.exit(0);
		
		int plength = args.length;
		
		for (int i = 0; i < plength ; i++) {
			System.out.println(args[i]);
		}
	}
}

Multiply.java

/*

@Program name: Multiply.java
@Usage: java Multiply <int row> <int col>

Main function throws NumberFormatException in case the user inputs something
that is not an a number.

*/


class Multiply {

	public static void main(String args[]) throws NumberFormatException {
		
		if(args.length < 2 ) {
			System.out.println("Usage: java Multiply rows cols");
			System.exit(0);
		}
		
		int row = Integer.parseInt(args[0]);
		int col = Integer.parseInt(args[1]);
		
		for (int irow = 1; irow <= row; irow++) {
			for (int jrow = 1; jrow <= row; jrow++) {
				System.out.print(irow * jrow + "\t");
			}
			System.out.print("\n");
		}
	}
}

Person.java

class Person {

	Person walk() {
		System.out.println("walking");
		return this;
	}

	Person talk() {
		System.out.println("talking");
		return this;
	}
	
	Person sleep() {
		System.out.println("sleeping");
		return this;
	}
	
	public static void main(String[] args) {
		
		new Person().walk().talk().sleep();
		
	}
}

Phone.java

/*
First example of inheritance
*/

class Phone {

	String number;

	
	Phone() {
	
	}
	
	void call(String numtocall) {
		System.out.println("Calling " + numtocall);	
	}
	
	void answer() {
		
		String color;
		
		System.out.println("Answering");
	}
	
	void setNumber(String args) {
		number = args;
		System.out.println("Number is " + number);
	}	
}

class MobilePhone extends Phone {

	void sms(String numtarget, String msg) {
		System.out.println("sending " + msg + " to " + numtarget);
	}
}

class TestPhone {
	public static void main(String[] args) {
		
		MobilePhone p = new MobilePhone();
		p.setNumber("12345");
		p.call("678910");
		p.answer();		
	}
}

Shape.java

class Shape {

	static int count=1;
	String color="";

}

class ShapeTest {

	public static void main(String[] args) {
		
		Shape square = new Shape();
		Shape circle = new Shape();
		Shape triangle = new Shape();
		
		square.color = "white";
		circle.color = "black";
		triangle.color = "red";
		
		System.out.println("square color " + square.color);
		System.out.println("circle color " + circle.color);
		System.out.println("triangle color " + triangle.color);

		System.out.println("square count " + square.count);

		square.count = 10;
		
		System.out.println("square count " + square.count);
		System.out.println("circle count " + circle.count);
		System.out.println("triangle count " + triangle.count);

		
	}

}

Swap.java

class John {
	String name = "John";
}

class Jane {
	String name = "Jane";
}

class Swap {
	
	John a = new John();
	Jane b = new Jane();
	
	void start() {
		swap(a,b);
		System.out.println("obj John -> " + a.name);
		System.out.println("obj Jane -> " + b.name);
	}
	
	void swap(John a, Jane b) {
		a.name = "Jane";
		b.name = "John";
	}
	
	public static void main(String[] args) {
		new Swap().start();
	}
}

SwapInt.java

class SwapInt {

	int x = 1;
	int y = 2;

	void start() {
		swap(x,y);
		
		System.out.println("x = " + x);
		System.out.println("y = " + y);
		
	}
	
	
	void swap(int a,int b) {
	
		int temp = a;
		a = b;
		b = temp;
		
		System.out.println("inside the function ------\n");
		
		System.out.println("x = " + a);
		System.out.println("y = " + b);
			
		System.out.println("finished on the function ----\n");
		
	}

	public static void main(String[] args) {
		new SwapInt().start();
	}

}

This is a test comment

Why won't the notification fire up on email