prototype屬性可以將屬性和方法新增到任何物件(Number, Boolean, String 和Date等)。
註:原型(Prototype)是一個全域性的屬性,它可以使用在幾乎所有的物件。
object.prototype.name = value
這裡有一個例子展示了如何使用原型(prototype)屬性的屬性新增到物件:
<html> <head> <title>User-defined objects</title> <script type="text/javascript"> function book(title, author){ this.title = title; this.author = author; } </script> </head> <body> <script type="text/javascript"> var myBook = new book("Perl", "Mohtashim"); book.prototype.price = null; myBook.price = 100; document.write("Book title is : " + myBook.title + "<br>"); document.write("Book author is : " + myBook.author + "<br>"); document.write("Book price is : " + myBook.price + "<br>"); </script> </body> </html>
這將產生以下結果:
Book title is : Perl Book author is : Mohtashim Book price is : 100