1. Consider a two-digit integer. Extract the digits. Write a Java program to form the reverse of the number and print it.
2. Consider a two-digit integer number. Find the difference and product of the digits and print them.
3. Consider two two-digit integers. Find the sum of their squares.
4. Consider the length and breadth of a rectangle. Find the area and the perimeter of the rectangle.
5. Consider the side of a square. Find the area and the perimeter of the square.

And your question(s) is/are ?

#1, #2, and #3

import java.io.*;

public class Foo {

	//Create a single shared BufferedReader for keyboard input
	private static BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

	// Program exectuon starts here
	public static void main(String args[]){

		// Get a two-digit number from the user
		int number = getTwoDigitNumber();

		// Extract digits
		int firstDigit = Math.abs(number / 10);
		int secondDigit = Math.abs(number % 10);

		// Print reverse
		System.out.println("Reverse: " + (new StringBuffer(Math.abs(number)+"").reverse()));

		// Print difference of digits
		System.out.println("Difference: " + firstDigit + " - " + secondDigit + " = " + (firstDigit - secondDigit));

		// Print product of digits
		System.out.println("Product: " + firstDigit + " * " + secondDigit + " = " + (firstDigit * secondDigit));
		
		// Get two two-digit number from the user
		number = getTwoDigitNumber();
		int number2 = getTwoDigitNumber();
		
		// Print sum of squares
		System.out.println(number + "^2  + " + number2 + "^2 = " + (number*number + number2*number2));

	}

	// Returns a two-digit number from the user
	public static int getTwoDigitNumber(){
		// Loop until valid input is entered
		while(true){
			try{
				// Prompt user for input
				System.out.print("Enter a two digit number: ");
				String input = in.readLine();
				int number = Integer.parseInt(input);
				if(number > -100 && number < -9 || number < 100 && number > 9){
					return number;
				}else{
					System.out.println("Invalid input. Please enter a valid two digit integer.");
				}
			}catch(Exception e){
				System.out.println("Invalid input. Please enter a valid two digit integer.");
			}
		}
	}
}

#4 and #5

import java.io.*;

public class Foo2 {

	// Create a single shared BufferedReader for keyboard input
	private static BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

	// Program exectuon starts here
	public static void main(String args[]){
		
		// Prompt user for dimensions of the rectangle
		double length = getValue("length", "rectangle");
		double breadth = getValue("breadth", "rectangle");
		
		// Truncate values to two decimal places
		java.text.DecimalFormat df = new java.text.DecimalFormat("#.##");
		
		// Print area and perimeter of the rectangle
		System.out.println("Area: " + df.format(length*breadth));
		System.out.println("Perimeter: " + df.format(length*2 + breadth*2));
		
		// Prompt user for dimensions of the square
		double sideLength = getValue("side length", "square");
		
		//  Print area and perimeter of the square
		System.out.println("Area: " + df.format(sideLength*sideLength));
		System.out.println("Perimeter: " + df.format(sideLength*4));
		
	}

	// Returns a number from the user
	public static double getValue(String measurement, String shape){
		// Loop until valid input is entered
		while(true){
			try{
				// Prompt user for input
				System.out.print("Enter the " + measurement + " of the " + shape + ": ");
				double number = Double.parseDouble(in.readLine());
				if(number > 0){
					return number;
				}else{
					System.out.println("Invalid input. Please enter a positive value.");
				}
			}catch(Exception e){
				System.out.println("Invalid input. Please enter a valid number.");
			}
		}
	}
}

This post has been edited by cutegrrl: 14 Jun, 2008 - 09:35 PM

Cutegrrl you are spoiling the newbie again....
don't forget the rules

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