Execution of $instance Definition Body

This section describes when the $instance definition body is executed.

To support object properties and methods, the system generated __new() construction function will execute the code that defines object properties in the $instance definition body.

Example showing the execution of $instance definition body:

$class user: {
   $instance x: {
      write("Adding object properties...");
      x.login = "guest";
      x.password = "DontTell";
      $method x.changePassword(newPassword): {
         x.password = newPassword;

# you will see the "Adding object properties..." message
# when the following statement is executed.
u = user(); # or user.__new();

# you will see the "Adding object properties..." message again
x = user();

Table of Contents

 About This Book

 Introduction of H Language


 Data Types




 "boolean" Data Type

 "integer" Data Type

 "string" Data Type

 "real" Data Type

 "array" Data Type

 Source Code Packages

Classes and Objects

 What Is Class

 What Is Object

 $class Statement - Create New Classes

 Class Variables and Functions

 Execution of $class Definition Body

 __new() - Object Constructor Function

 $instance Statement - Define Instance Template

Execution of $instance Definition Body

 Access Object Properties

 $method Statement - Define Object Method

 Access Object Methods

 _first() Method - Object Initialization

 Access Class Variables from Object Methods

 __delete() - Object Destructor Method

 $delete Statement - Delete Objects

 _last() Method - Object Cleanup

 Object Oriented Programming

 Inheritance - Object Attachments

 Encapsulation - Private Members


 Full Version in PDF/ePUB