Example 08 01 singleobject constructor

chp08_objects/example_08_01_singleobject/sketch.js

@@ -4,36 +4,41 @@
 
 // Example 8-1: A Car class and a Car object
 
-var car; // Declare car object as a global variable.
+let car; // Declare car object as a global variable.
 
 function setup() {
   createCanvas(480, 270);
   // Initialize Car object
-
-  car = {
-    c: color(175),
-    xpos: width/2,
-    ypos: height/2,
-    xspeed: 3,
-    display: function() { // Function.
-      // The car is just a square
-      rectMode(CENTER);
-      stroke(0);
-      fill(this.c);
-      rect(this.xpos,this.ypos,20,10);
-    },
-    move: function() { // Function.
-      this.xpos = this.xpos + this.xspeed;
-      if (this.xpos > width) {
-        this.xpos = 0;
-      }
-    }
-  };
+  car = new Car();
 }
 
 function draw() {
   background(100);
   // Operate Car object.
-  car.move(); // Operate the car object in draw( ) by calling object methods using the dots syntax.
+  car.move(); // 
   car.display();
 }
+
+class Car {
+  constructor(c, x, y, xspeed) {
+    this.c = color(175);
+    this.x = width/2;
+    this.y = height/2;
+    this.xspeed = 3;
+  }
+
+  display() { 
+    // The car is just a square
+    rectMode(CENTER);
+    stroke(0);
+    fill(this.c);
+    rect(this.x, this.y, 20, 10);
+  }
+
+  move() { 
+    this.x = this.x + this.xspeed;
+    if (this.x > width) {
+      this.x = 0;
+    }
+  }
+}