Prestwood Computer Dictionary

Member-driven Prestwood Computer Dictionary. Your participation is requested!
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Each list is compiled from the cooresponding community group.
New Terms:
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KB Article |
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Mike Prestwood
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1. Member Event
A custom event added by a programmer to a class. Custom created events need to be processed, usually by an event dispatcher within a framework.
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 Definition
 8706 Hits
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 Coding & OO
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Mike Prestwood
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2. Event Handler
In computer programming, an event handler is part of event driven programming where the events are created by the framework based on interpreting inputs. Each event allows you to add code to an application-level event generated by the underlying framework, typically GUI triggers such as a key press, mouse movement, action selection, and an expired timer. In addition, events can represent data changes, new data, etc. Specifically, an event handler is an asynchronous callback subroutine that handles inputs received in a program.
A custom event is a programmer created event. For example, you can contrast an event handler with a member event, an OOP concept where you add an event to a class.
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 Definition
 10294 Hits
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 Coding & OO
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Mike Prestwood
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3. Windows Internet Name Service (WINS)
Microsoft's implementation of NetBIOS Name Service (NBNS), a name server and service for NetBIOS computer names. Just as DNS serves up domain names, WINS serves up NetBios names and is particularly useful within a Microsoft-based network when or without the NetBIOS protocol installed. Use of WINS will decrease broadcast traffic.
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 Definition
 8821 Hits
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 Computer Tech
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Mike Prestwood
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4. Delphi Prism Self Keyword (Self)
Within the implementation of a method, the identifier Self references the object in which the method is called. The Self variable is an implicit parameter for each object method. A method can use this variable to refer to its owning class.
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 Definition
 8703 Hits
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 Delphi Prism
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Mike Prestwood
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5. Code Contract
A.k.a. Class Contract and Design by Contracts.
A contract with a method that must be true upon calling (pre) or exiting (post). A pre-condition contract must be true when the method is called. A post-condition contract must be true when exiting. If either are not true, an error is raised. For example, you can use code contracts to check for the validity of input parameters, and results
An invariant is also a code contract which validates the state of the object required by the method.
13 years ago, and updated 13 years ago
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 Definition
 8805 Hits
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 Coding & OO
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Mike Prestwood
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6. Pointers / References
A pointer is a variable type that allows you to refer indirectly to another object. Instead of holding data, a pointer holds the address to data -- the address of another variable or object. You can change the address value a pointer points to thus changing the variable or object the pointer is pointing to.
A reference is a type of pointer that cannot change and it must always point to a valid storage (no nulls).
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 Definition
 14003 Hits
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 Coding & OO
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Mike Prestwood
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7. Class Helper
A. In Dephi, class helpers allow you to extend a class without using inheritance. With a class helper, you do not have to create and use a new class descending from a class but instead you enhance the class directly and continue using it as you always have (even just with the DCU).
B. In general terms, developers sometimes use the term to refer to any class that helps out another class.
13 years ago, and updated 13 years ago
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 Definition
 10316 Hits
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 Coding & OO
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Mike Prestwood
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8. Inline Routines
Instead of calling a routine, you move the code from the routine itself and expand it in place of the call. In addition to manual inlining, some languages support automatic inlining where the compiler or some other pre-compiler decides when to inline a code routine. Also, some languages allow for developer defined inlining where the developer can suggest and/or force the inlining of a code routine. Inlining can optimize your code for speed by saving a call and return, and parameter management.
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 Definition
 13928 Hits
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 Coding & OO
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Mike Prestwood
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9. Class Destructor
A special class method called when an object instance of a class is destroyed. With some languages they are called when the object instance goes out of scope, with some languages you specifically have to call the destructor in code to destroy the object, and others use a garbage collector to dispose of object instances at specific times.
Desctructors are commonly used to free the object instance but with languages that have a garbage collector object instances are disposed of when appropriate. Either way, destructors or their equivalent are commonly used to free up resources allocated in the class constructor.
13 years ago, and updated 13 years ago
(1 Comments
, last by Roked1948.R )
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 Definition
 18820 Hits
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 Coding & OO
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Mike Prestwood
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10. Method Overriding
Where you define or implement a virtual method in a parent class and then replace it in a descendant class.
When you decide to declare a method as virtual, you are giving permission to derived classes to extend and override the method with their own implementation. You can have the extended method call the parent method's code too.
In most OO languages you can also choose to hide a parent method. When you introduce a new implementation of the same named method with the same signature without overriding, you are hiding the parent method.
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 Definition
15523 Hits
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 Coding & OO
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Updated Terms:
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KB Article |
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Wes Peterson
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1. RAID
RAID is the acronym for a Redundant Array of Independent Drives. RAID specifies several "levels," 0, 1, etc. Different levels provide different options. One level allows you to combine multiple smaller drives into one, huge volume. Another level offers tremendous performance boosts by "striping" data across multiple drives such that reads and writes are split across the drives. If one drive fails, the other takes over until the bad drive is replaced. Once replaced, the RAID subsystem automatically restores the mirror.
14 years ago, and updated 12 years ago
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 Definition
 13010 Hits
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 Computer Tech
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Mike Prestwood
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2. Paradox Net Dir
The directory location of the Paradox network control file PDOXUSRS.NET. The active NET DIR parameter is stored in the Paradox section of the BDE configuration file and has precedence over any other NET DIR parameters that may be stored in older 16-bit configuration files, or in the System Init section of the current configuration file, or in the Registry. These other NET DIR entries will have no effect. To access a Paradox table on a network drive, the active NET DIR parameter in the Paradox section of the BDE configuration file must point to a network drive and folder in common to all users.
14 years ago, and updated 13 years ago
(4 Comments
, last by Hugh.R )
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 Definition
41972 Hits
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 Corel Paradox / ObjectPAL Coding
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Mike Prestwood
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3. PSDP Checkpoints
A checkpoint is NOT a task, but rather a milestone. A point in the project that marks significant progress. Although PSDP contains many standard checkpoints, the executive sponsor and project manager must agree on the checkpoints they wish to track. Once established, tasks can be associated with a checkpoint and you can easily view what tasks are completed per checkpoint and what checkpoints do NOT have tasks established yet.
14 years ago, and updated 13 years ago
(4 Comments
, last by Andrew.M2 )
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 Definition
14105 Hits
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 PM, Process, and PSDP
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Mike Prestwood
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4. Interface
An element of coding where you define a common set of properties and methods for use with the design of two or more classes.
Both interfaces and abstract classes are types of abstraction. With interfaces, like abstract classes, you cannot provide any implementation. However, unlike abstract classes, interfaces are not based on inheritance. You can apply an Interface to any class in your class tree. In a real sense, interfaces are a technique for designing horizontally in a class hierarchy (as opposed to inheritance where you design vertically). Using interfaces in your class design allows your system to evolve without breaking existing code.
14 years ago, and updated 13 years ago
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 Definition
 25137 Hits
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 Coding & OO
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Mike Prestwood
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5. Member Field
Also known as a Class Field.
A class variable defined with a specific class visibility, usually private visibility. A member property is different than a member field. A member property uses a member field to store values through accessor methods (getters and setters). For example, it is common to use a private member field to store the current value of a property. The current values of all the class member fields is the current state of the object.
14 years ago, and updated 13 years ago
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 Definition
 11288 Hits
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 Coding & OO
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Mike Prestwood
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6. Class Helper
A. In Dephi, class helpers allow you to extend a class without using inheritance. With a class helper, you do not have to create and use a new class descending from a class but instead you enhance the class directly and continue using it as you always have (even just with the DCU).
B. In general terms, developers sometimes use the term to refer to any class that helps out another class.
13 years ago, and updated 13 years ago
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 Definition
 10316 Hits
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 Coding & OO
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Mike Prestwood
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7. Code Contract
A.k.a. Class Contract and Design by Contracts.
A contract with a method that must be true upon calling (pre) or exiting (post). A pre-condition contract must be true when the method is called. A post-condition contract must be true when exiting. If either are not true, an error is raised. For example, you can use code contracts to check for the validity of input parameters, and results
An invariant is also a code contract which validates the state of the object required by the method.
13 years ago, and updated 13 years ago
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 Definition
 8805 Hits
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 Coding & OO
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Mike Prestwood
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8. Member Method
Also known as a Class Method.
A code routine that belongs to the class or an object instance (an instance of the class). Methods that belong to the class are called class methods or static methods. Methods that belong to an object instance are called instance methods, or simply methods.
When a method returns a value, it is a function method. When no value is returned (or void), it is a procedure method.
Methods frequently use method parameters to transfer data. When one object instance calls another object instance using a method with parameters, you call that messaging.
13 years ago, and updated 13 years ago
(1 Comments
, last by Andrew.S2 )
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 Definition
 10227 Hits
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 Coding & OO
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Mike Prestwood
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9. Abstract Class / Abstract Member
An abstract class member is a member that is specified in a class but not implemented. Classes that inherit from the class will have to implement the abstract member. Abstract members are a technique for ensuring a common interface with descendant classes. An abstract class is a class you cannot instantiate. A pure abstract class is a class with only abstract members.
14 years ago, and updated 13 years ago
(5 Comments
, last by AkaRasty.B )
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 Definition
 23292 Hits
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 Coding & OO
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Mike Prestwood
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10. Method Overriding
Where you define or implement a virtual method in a parent class and then replace it in a descendant class.
When you decide to declare a method as virtual, you are giving permission to derived classes to extend and override the method with their own implementation. You can have the extended method call the parent method's code too.
In most OO languages you can also choose to hide a parent method. When you introduce a new implementation of the same named method with the same signature without overriding, you are hiding the parent method.
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 Definition
15523 Hits
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 Coding & OO
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