Complex.java

/* *****************************************************************************
 *  Name:              Ada Lovelace
 *  Coursera User ID:  123456
 *  Last modified:     October 16, 1842
 **************************************************************************** */

public class Complex {
    private final double re, im;

    public Complex(double real, double imaginary) {
        re = real;
        im = imaginary;
    }

    public Complex plus(Complex b) {
        double real = re + b.re;
        double imaginary = im + b.im;
        return new Complex(real, imaginary);
    }

    public Complex times(Complex b) {
        double real = re * b.re - im * b.im;
        double imaginary = re * b.im + im * b.re;
        return new Complex(real, imaginary);
    }

    public double abs() {
        return Math.sqrt(re * re + im * im);
    }

    public String toString() {
        return re + " + " + im + "i";
    }

    public static void main(String[] args) {
        Complex a = new Complex(3, -4);
        Complex b = new Complex(12, 5);
        System.out.println("a = " + a + "\n" + "b = " + b);
        System.out.println("a+b = " + a.plus(b));
        System.out.println("a*b = " + a.times(b));
    }
}