Method Abstract():init() Foundation

The method :init() can optionally be declared within the class declaration (between the CLASS...ENDCLASS statements). If it is declared, it is executed immediately after calling the class method :new(), i.e. as soon as a new instance of the class (the new object) is created. The method is used to initialize instance variables of the object with default values. If :init() is declared, it must be implemented for the class. The same arguments are passed to the instance method :init() as to the class method :new(). Within the source code of the method :init(), the object can be referenced through the variable self. The operator :: can also be used (as an abbreviation for self:) to send a message to the object.

When a class is derived from other classes (superclasses), and the superclasses have their own :init() methods, the :init()method of each such superclass must be explicitly called from within the subclass :init():, by using the superclasses name. However, if :init() is not declared in a subclass, the :init() method of the superclass is implicitly executed when an object of the subclass is created.