Hello:
My current assignmen is to create methods of arithmetic operations for two
sets of complex numbers (ordered pairs ab and cd) with the default value set
to (0, 0) for both. I was able (with some help from the internet) to
establish the code for this. However, I now need to take in values from a
user to override the default values. So if the default values of ab and cd
are (0, 0) and (0, 0), a user can type in (1, 2) and (3, 4) and add, subtract,
multiply and divide these complex numbers. As I said, I have the code for the
arithmetic, but can't get the user input part. I checked out a link that was
on this site that gave IO code and was stumped by the code - it didn't make
any sense to me.

I hope someone could help me - as you can tell by my previous posts, I am a
newbie. By the way, is it ok to post the code? As I said, I am a newbie.
Thanks so much.

import java.text.*;
import java.io.*;
import java.lang.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class Program9  {

     public double real;
     public double imagn;

     //Constructor that initializes the values
    Program9  (double a, double b) {
          real = a;
       imagn = b;
    }

     //Get methods for real & imaginary numbers
     public double realPart() {
       return real;
     }

    public double imagnPart() {
       return imagn;
    }

    //Add method
    public void add (Program9 cvalue) {
          real = real + cvalue.real;
       imagn  = imagn  + cvalue.imagn;
     }//end add

     //Subtract method
    public void subtract (Program9 cvalue) {
       real = real - cvalue.real;
       imagn  = imagn  - cvalue.imagn;
    }//end subtract

     //Define a static add method that creates a new complex object with the
sum.
     public static Program9 add (Program9 cvalue1, Program9 cvalue2) {
       double a = cvalue1.real + cvalue2.real;
          double b = cvalue1.imagn  + cvalue2.imagn;
       return new Program9 (a,b);
     }//end sum method

     //Define a static subtraction method that creates a new complex object
with the product
   public static Program9 subtract (Program9 cvalue1, Program9 cvalue2) {
          double a = cvalue1.real - cvalue2.real;
         double b = cvalue1.imagn  - cvalue2.imagn;
       return new Program9 (a,b);
     }//end subtract method

     //Provide the absolute value of the ordered pairs
     public double modulus () {
       return Math.sqrt((real * real) + (imagn * imagn));
     }//end abvalue

     //Multiply this object by the argument
    public void multiply (Program9 cvalue) {
       double a2 = real * cvalue.real - imagn * cvalue.imagn;
       double b2 = real * cvalue.imagn  + imagn * cvalue.real;
           real = a2;
           imagn = b2;
     }//end multiply  arg

     //Define a static multiply method that creates a new object with the
product.
    public static Program9 multiply (Program9 cvalue1, Program9 cvalue2) {
       double a2 = cvalue1.real * cvalue2.real - cvalue1.imagn * cvalue2.imagn;
       double b2 = cvalue1.imagn * cvalue2.real + cvalue1.real * cvalue2.imagn;
          return new Program9(a2, b2);
    }//end multiply method

     //Divide this object by the argument
    public void divide (Program9 cvalue) {
       double dvd = cvalue.real * cvalue.real + cvalue.imagn * cvalue.imagn;
       double a = real * cvalue.real + imagn * cvalue.imagn;
        double b = imagn * cvalue.real - real * cvalue.imagn;
           real = a/dvd;
           imagn  = b/dvd;
     }//end divide arg

    //Define a static divide method that creates a new object with the result of
     public static Program9 divide (Program9 cvalue1, Program9 cvalue2) {
       double dvd = cvalue2.real * cvalue2.real + cvalue2.imagn  * cvalue2.
imagn;
        double a = cvalue1.real * cvalue2.real + cvalue1.imagn  * cvalue2.imagn;
        double b = cvalue1.imagn * cvalue2.real - cvalue1.real * cvalue2.imagn;
       return new Program9 (a/dvd, b/dvd);
    } // end divide method

    // Return a string representation of the complex value
    public String toString () {
       String imagn_sign = (imagn < 0) ? " - " : " + ";
       return (real +  imagn_sign + imagn + "i");
     }//end string method

    public static void main ( String args[] ) throws IOException {
        BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in))
;

            // Create complex objects
            Program9 ab = new Program9 (0, 0);
            Program9 cd = new Program9 (0, 0);

        Program9 testAdd = Program9.add (ab,cd);
          Program9 testMult = Program9.multiply (ab,cd);
          Program9 testDivide = Program9.divide (ab,cd);
          Program9 testSubtract = Program9.subtract (ab,cd);

          System.out.println("Complex numbers " + ab + " and " + cd + " added are
" + testAdd);
          System.out.println("Complex number " + ab + " subtracted from " + cd + "
is " + testSubtract);
          System.out.println("Complex numbers " + ab + " and " + cd + " multiplied
together is " + testMult);
          System.out.println("Complex numbers " + ab + " divided by " + cd + "
equals " + testDivide);
    }//end of main
}//end of Program9