Can someone explain this Complex number class in Java in detail? What do things like 'o.real' and 'o.conjugate' do, along with the other methods. Tracking this code is getting confusing so any comments someone can make telling me what each method is doing and how would be great. Also, why do I get a 'i' at the end of the number when I run this program? Still new to programming so just trying to get the hang of it.

public class Main {

public static void main(String[] args) {

Complex a = new Complex(2.0, 3.0); Complex b = new Complex(1.0, 2.0);

System.out.println(a + " + " + b + " = " + a.add(b)); System.out.println(a + " - " + b + " = " + a.sub(b)); System.out.println(a + " * " + b + " = " + a.mul(b)); System.out.println(a + " / " + b + " = " + a.div(b)); } }

class Complex {

public Complex(double real, double imag) {

this.real = real; this.imag = imag; }

public Complex add(Complex o) {

return new Complex(real + o.real, imag + o.imag); }

private Complex conjugate() {

return new Complex(real, -imag); }

public Complex div(Complex o) {

Complex top = mul(o.conjugate()); Complex bot = o.mul(o.conjugate());

return new Complex(top.real / bot.real, top.imag / bot.real); }

public Complex mul(Complex o) {

return new Complex(real * o.real - imag * o.imag, real * o.imag + imag * o.real); }

public Complex sub(Complex o) {

return new Complex(real - o.real, imag - o.imag); }

public String toString() {

return "(" + real + (imag < 0.0 ? " - " : " + ") + (imag < 0.0 ? -imag : imag) + "i)"; }

private double real; private double imag; }