appendixA.java

import java.io.*;

/**
 * This class demonstrates documentation comments.
 * @author Herbert Schildt
 * @version 1.2
*/
public class SquareNum {
  /**
   * This method returns the square of num.
   * This is a multiline description. You can use
   * as many lines as you like.
   * @param num The value to be squared.
   * @return num squared as a double.
  */
  public double square(double num) {
    return num * num;
  }

  /**
   * This method inputs a number from the user.
   * @return The value input as a double.
   * @exception IOException On input error.
   * @see IOException
  */
  public double getNumber() throws IOException {
    // create a BufferedReader using System.in
    InputStreamReader isr = new InputStreamReader(System.in);
    BufferedReader inData = new BufferedReader(isr);
    String str;

    str = inData.readLine();
    return (new Double(str)).doubleValue();
  }

  /**
   * This method demonstrates square().
   * @param args Unused.
   * @exception IOException On input error.
   * @see IOException
  */
  public static void main(String[] args)
    throws IOException
  {
    SquareNum ob = new SquareNum();
    double val;

    System.out.println("Enter value to be squared: ");
    val = ob.getNumber();
    val = ob.square(val);

    System.out.println("Squared value is " + val);
  }
}