UserDataRecord :: init ( 'UserDataRecord', 'users', $db ) Return $result // An array of UserDataRecord objects Short example on a DataRecord class without error checking: By doing so you also don't have to redefine $a for the subclasses and the superclass' $a can be private. Turn static $a on class A into an array, use classnames of subclasses as indeces. BUT: This would produce redundant data on every object of the class. If the init() method looks the same for (almost) all subclasses there should be no need to implement init() in every subclass and by that producing redundant code. On PHP 5.2.x or previous you might run into problems initializing static variables in subclasses due to the lack of late static binding: Parent: parent_only=fromchild, both_distinct=fromparentĬhild: parent_only=fromchild, both_distinct=fromchild, child_only=fromchild Static properties defined ONLY in the parent class will share a COMMON value.Įcho 'Child: parent_only=', staticchild :: $parent_only, ', both_distinct=', staticchild :: $both_distinct, ', child_only=', staticchild :: $child_only, "\r\n" static:: are crucial inside of child methods to reference the intended static property. Static properties defined in both parent and child classes will hold DISTINCT values for each class. It is important to understand the behavior of static properties in the context of class inheritance: Thus, in your example, the static property has the correct value, according to principles of object oriented conception. That is, a static member is shared by all instances of a class although a non static member exists for each instance of class. The difference between static and non static members is only that a non static member is tied to an instance of a class although a static member is tied to the class, and not to a particular instance. Members are shared through inheritance, and can be accessed by derived classes according to visibility (public, protected, private). You misunderstand the meaning of inheritance : there is no duplication of members when you inherit from a base class. Getting Started Introduction A simple tutorial Language Reference Basic syntax Types Variables Constants Expressions Operators Control Structures Functions Classes and Objects Namespaces Enumerations Errors Exceptions Fibers Generators Attributes References Explained Predefined Variables Predefined Exceptions Predefined Interfaces and Classes Predefined Attributes Context options and parameters Supported Protocols and Wrappers Security Introduction General considerations Installed as CGI binary Installed as an Apache module Session Security Filesystem Security Database Security Error Reporting User Submitted Data Hiding PHP Keeping Current Features HTTP authentication with PHP Cookies Sessions Dealing with XForms Handling file uploads Using remote files Connection handling Persistent Database Connections Command line usage Garbage Collection DTrace Dynamic Tracing Function Reference Affecting PHP's Behaviour Audio Formats Manipulation Authentication Services Command Line Specific Extensions Compression and Archive Extensions Cryptography Extensions Database Extensions Date and Time Related Extensions File System Related Extensions Human Language and Character Encoding Support Image Processing and Generation Mail Related Extensions Mathematical Extensions Non-Text MIME Output Process Control Extensions Other Basic Extensions Other Services Search Engine Extensions Server Specific Extensions Session Extensions Text Processing Variable and Type Related Extensions Web Services Windows Only Extensions XML Manipulation GUI Extensions Keyboard Shortcuts ? This help j Next menu item k Previous menu item g p Previous man page g n Next man page G Scroll to bottom g g Scroll to top g h Goto homepage g s Goto search
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