UML Class Diagram

Object

Concrete member of a class

Physical

Deployment diagram

Dynamic

State machine, activity diagram, sequence diagram, communication diagram, timing diagram, and interaction overview diagram

Overriding

a method would be inherited from a superclass, but a subclass contains a new version of the method instead

Occurence

a set of related objects that share common information but also differ from each other in important ways

generalization

a taxonomic relationship between a more general and more specific element. The more specific element is fully consistent with the more general element and contains additional information.

modifier

alter the state of an object

polymorphism

an abstract operation may be performed in different ways in different classes, requires that there be multiple methods of the same name, reduces the need for programmers to code many if-else or switch statements

association

basic relationship, an object can only interact with another object with which it has an explicit or implicit relationship

Structural

class diagram, object diagram, composite structure diagram, component diagram, and use case diagram

Modularity

code can be constructed entirely from a set of classes

constructor

create, build, and initialize an object

class

data abstraction that contains procedural abstractions that operate on its instances(objects)

class diagram

defines all possible sets of runtime instances and their relationships

Class

description for a set of similar objects that have the same structure and behavior(i.e. its instances).

destructor

destroy an object

type of variable

determines what classes of objects it may contain

Interface

essentially an abstract class, but cannot have executable statements, defines a set of operations that make sense in several classes

isa rule - inheritence

ex. A checkingAccount is an Account but a province is not a country!

iterator

for objects that encapsulate a collection of other objects, access all parts of a composite object, and apply some action to each of the parts

method

implementation of an operation

Encapsulation

in addition to abstraction, leads to information hiding, which allows for more maintainable, evolvable systems

Object

is instantiated, a conscious decision by a software engineer designates this as an instance of a class, they interact with each other at runtime

identity

key concept of object orientation: each object is distinct from each other object, and can be referred to. 2 objects(twins) are distinct even if they have the same data

private, protected, public, package(default)

levels of visibility

abstract class

like a regular class but it cannot be instantiated(name indicated in italics)

dynamic binding

occurs when the decision about which method to run can only be made at runtime, needed when: a variable is declared to have a superclass as its type and there is more than one possible polymorphic method that could be run among the type of the variable and its subclasses

Model Management

package diagrma

Aggregation

part-whole relationship, not tied to life cycle, transitive and antisymmetric

Composition

part-whole relationship; life-cycles of children objects are tied to their parent, so when the parent is destroyed so are the children; transitive and antisymmetric

Association

represents a relationship between 2 classes, bi directional

reasons for overriding

restriction, extension, optimization

an object class

result of physical composition/aggreggation

observer

retrieve information about the state of an object

Class Variable

shared by all instances, useful for default values or constants, useful for lookup tables or similar structures used by operations

Attribute

simple piece of data, exists when the object exists (has no instance on its own)

class vs. instance

something belongs to a class if it could have instances. In general, something should be an instance if it is clearly a single member of the set defined by a class

operation

specification of a transformation or query that an object may be called to execute

enumeration

specifies a predefined list of choices, defined within the class that needs this

Multiplicity(m)

specifies how many instances of one class relate to how many instances of another class

life cycle of an object

the identity of an object never changes during its lifetime, an attribute of an object doesn't have identity

inheritance

the mechanism by which more specific elements incorporate structure and behavior defined by more general elements. ie implicit possession by a subclass of features defined in a superclass

Reification

the process of making out of a concept an object(class), often applied to non physical composition/aggregation

Association Class

use when an attribute that relates to 2 associated classes cannot be placed into either one of them.

Instance Variable

variables used to implement attributes and those used to implement associations

field

what an association is implemented as