Chap8 Class&MethodDesign

Visibility

The access level of attributes and methods

Private

accessible only within the class.

Protected

accessible within the class and its subclasses.

Public

accessible by any class.

Exception

An error or violation of a constraint detected during program execution.

Fan-Out

The number of methods or classes that depend on a single module; lower fan-out means lower coupling.

Signature

The name, parameters, and return type that uniquely identify a method.

Protocol (Signature)

The full definition of a method's name, parameters, and return type that determines how it can be called.

Postcondition

A rule that must be true after a method finishes executing.

Precondition

A rule that must be true before a method begins executing.

Invariant

A condition that must always remain true for an object throughout its lifetime.

Framework

A collection of implemented, extendable classes that provides a base structure for developing an application.

Class Library

A reusable collection of pre-written classes that provide general-purpose functionality such as math, file management, or user interface elements.

Component

A self-contained, encapsulated piece of software with a well-defined API that can be plugged into a system to provide specific functionality.

API (Application Program Interface)

A defined set of method calls or interfaces that allow external programs or components to interact with a system or object.

Normalization

The process of restructuring design elements to eliminate redundancy and identify missing classes or attributes.

Derived Attribute

An attribute whose value is calculated from other attributes (e.g., total = price × quantity).

Active Value

A stored or cached computed value that updates automatically when any of its input attributes change.

Caching Computational Results

Storing calculated results (like totals) to avoid recomputation every time the value is needed.

Object-Based Language

A programming language that supports objects but does not support inheritance (e.g., Visual Basic).

Object Constraint Language (OCL)

A formal UML language used to express constraints, preconditions, postconditions, and invariants.

Structured English

A precise, English-like language used to describe algorithms or method logic.

Method Specification

A written description that defines what a method does, its inputs, outputs, and constraints for coding implementation.

Event Driven

A programming approach where the system waits for events and executes specific methods in response to them.