JavaScript and Class Object การสร้างและใช้งานคลาสใน JavaScript

<script type="text/javascript">
     var product_names = new Array();
     var product_prices = new Array();
     var product_qtys = new Array();
     product_names[0] = "Product 1";
     product_prices[0] = 200.00;
     product_qtys[0] = 3;

     product_names[1] = "Product 2";
     product_prices[1] = 210.00;
     product_qtys[1] = 2;

     product_names[2] = "Product 3";
     product_prices[2] = 220.00;
     product_qtys[2] = 6;

     // คำนวนราคารวม
     var sum = 0;
     for(var i = 0; i < product_prices.length; i++) {
          document.write(product_names[i] + " total price =  " +  (product_qtys[i] * product_prices[i]) + "<br />");
          sum += product_qtys[i] * product_prices[i];
     }
     document.write("Sum : " + sum.toFixed(2));
</script>

<script type="text/javascript">
     var Product = function(name, price, qty) {
          this.Name = name;
          this.Price = price;
          this.Qty = qty;

          this.GetTotalPrice= function() {
               return this.Price * this.Qty;
          }
          this.ToString = function() {
               return this.Name + " total price : " + (this.Qty * this.Price);
          }
     }
</script>

<script type="text/javascript" src="product.js"></script>
<script type="text/javascript">
// อาเรย์เอาไว้เก็บกลุ่มของ product
var products = new Array();
products[0] = new Product("Product 1", 200.00, 3);
products[1] = new Product("Product 2", 210.00, 2);
products[2] = new Product("Product 3", 220.00, 6);

// เปลี่ยนแปลงค่าได้ด้วยครับ
products[0].Name = "My product";
products[2].Qty = 1;

// ทดลองแสดงผล
var sum = 0.0;
for(var i = 0; i < products.length; i++) {
     document.write(products[i].ToString() + "<br />");
     sum += products[i].GetTotalPrice();
}
document.write("Total price : " + sum.toFixed(2));
</script>

var Product = function(name, price, qty) {
  this.Name = name;
  this.Price = price;
  this.Qty = qty;
  var vat = 1.7;

  this.GetTotalPrice= function() {
	   return this.Price * this.Qty;
  }
  this.ToString = function() {
	   return this.Name + " total price : " + (this.Qty * this.Price);
  }
  this.GetIncludeVatPrice = function() {
       return this.Price * vat;
  }
 }