Basics Flashcards
Class?
A blueprint that defines the variables and the method common to all objects of a certain kind.
Object?
Instances of a specific class.
A self-contained component which consists of methods and properties to make a particular type of data useful
Subclassing?
A subclass reuses code from a base class, or the superclass
Static methods?
Methods can be called without creating an object of a class
Instance methods?
Methods that requires an object of the class before the method can be called.
To invoke, create an object of the class within which the method is contained
Variable?
Containers for storing datavalues (int, string…)
Attribute?
Metadata of a programs objects, whilst a variable is a program object
Abstract class?
Can not be instantiated, but can be subclasses. Define the base-behaviour of subclasses(objects)
Interfaces?
Completely abstract class used to group related methods with empty bodies. All methods defined by an interface must appear in a class which implements said interface
Static types?
A type defined during compilation, and will be same throughout. Benefit that faults can be detected early and fix them.
Dynamic types?
Data decided at run-time(run-time polymorphism)
Interface inheritance?
When a class implements an interface, it and its subclasses inherit the methods within the interface
Dynamic binding?
Choice between several different possible implementations of a polymorphic method(i.e. an overriden method), decided at run-time
Primitive types?
There are 8 primitve types… Stores values
Reference types?
Hold a reference to objects and provides a means to access those objects stored somewhere in memory. Includes integers, Arrays, Strings
Overloading?
Two methods have the same nam, which one is chosen is at compilation(static)
Overriding?
Subclasses overrides a method created in a superclass. Used when the implementation of a certain behaviour must be determined dynamically, stemming from the objects handling behaviour differently. Method is polymorphic.
Encapsulation?
Information-hiding mechanism. Must declare class variables/attributes as private and provide public getters and setters.
Superclass?
A class that defines the standard behaviour for subclasses which create objects
Subclass?
A specific subtype of an object type, that inherits the attributes of the superclass
Constructors?
Called at the creation of an object. It is defined in the class of the object, and should always have the same name as the class it is contained within. Not implicitly inherited by subclasses from superclasses. Its job is to initialize the instance varaibles of the object.
Initilization?
Is a line of coe placed outside any method. Gives a variable its inital data
Aliasing?
Means that more than one reference is tied to the same object
