//  HowTo write Functions with a Variable Number of arguments
// James Brink    2/10/2020
 
// Globals
let commandColor;
let resultColor;
let sectionColor;
let example1Color

// Example 1 function
function testing(a, b, c) {
  var s = "a: " + a  +  ", b: " + b + ", c: " + c;
  if (a == null) {
    s += ". There are no arguments";
  }
  return s;
}
// Example 2 class
class Person {
  constructor(itsFirstName, itsLastName) {
    this.firstName = itsFirstName;
    this.lastName = itsLastName;
  }  
  name(f, l){
    if (f == null) {
      return this.firstName + " " + this.lastName;
    }
    this.firstName = f;
    if (l != null) {
      this.lastName = l;
    }
    return;
  } // name
} // end person
      
// Required setup
function setup() {
  let canvas = createCanvas(450, 290);
  canvas.parent("p5-left");
  sectionColor = color(0, 0, 0);
  example1Color = color(100, 0, 100);
  commandColor = color(60, 60, 0);
  resultColor = color(0, 100, 100);
} // setup

// show the results
function draw() {
  background(color(168, 168, 255));
  // Example 1
  fill(sectionColor);
  text('Example 1', 1, 20);
  fill(example1Color);
  text('testing(10, 20, "book") = ' + testing(1, 2, "book"), 20, 40);
  text('testing(10, 20) = ' + testing(10, 20), 20, 60);
  text('testing(10) = ' + testing(10), 20, 80);
  text('testing() = ' + testing(), 20, 100);
  // Example 2
  fill(sectionColor);
  text('Example 2', 1, 140);
  text('Code', 50, 160);
  text('Result', 250, 160);
  let child = new Person("John", "Doe");
  fill(commandColor);
  text('let child = new Person("John", "Doe");', 50, 180);
  text('child.name();', 50, 200);
  fill(resultColor);
  text(child.name(), 250, 200);

  child.name("Sally");
  fill(commandColor);
  text('child.name("Sally");' , 50, 220);
  text('child.name();', 50, 240);
  fill(resultColor);
  text(child.name(), 250, 240);
  
  child.name("Mary", "Smith");
  fill(commandColor);
  text('child.name("Mary", "Smith");', 50, 260);
  text('child.name();', 50, 280);
  fill(resultColor);
  text(child.name(), 250, 280);
}  // draw