WEEK#6 Object-oriented Programming Concepts
Stack: in a stack, you remove items
in reverse order you insert them, so the first item removed is the most
recently-added.
ADT(abstract data type): An ADT
describes how it stores data, and what operations(methods) one can perform on
this data.
This is abstract because there is no
code required to understand an ADT.
Class
Class: A user-defined prototype for an object
that defines a set of attributes that characterize any object of the class. The
attributes are data members(class variables and instance variables) and
methods, accessed via dot notation.
Class variable: A variable that that is shared
by all instances of a class. Class variables are defined within a class but
outside any of the class’s methods. Class variables aren’t used as frequently
as instance variables are.
Instance
variable: A variable that is defined inside a method and belongs only to the
current instance of a class.
Inheritance: The transfer of the
characteristics of a class to other classes that are derived from it.
Method: A special kind of function
that is defined in a class definition.
Object: A unique instance of a data
structure that’s defined by its class. An object comprises both data members (class
variables and instance variables) and method.
Operator overloading: The assignment
of more than one function to particular operator.
Exception: the purpose of the
Exceptin is to stop the program woth a meaningful message if there is an
advertent executin path that would return NoneType.
Recursion
Recursion means “defining something in
terms of itself” usually at some smaller scale, perhaps multiple times, to
achieve your objective.
Data Structure:The organization of data for the purpose
of making it easier to use is called a data
structure
recursive call : The
statement inside the function definition in which the function calls itself is
known as the recursive call.
base case: It does not lead to a recursive call: the case where
the element is not a (sub-) list. Without a base case, you’ll have infinite recursion, and your program will not work.
## base case: A branch of the
conditional statement in a recursive function that does not give rise to
further recursive calls.
## infinite recursion: A function that calls
itself recursively without ever reaching any base case. Eventually, infinite
recursion causes a runtime error.
## recursion: The process of calling a
function that is already executing.
##recursive call: The statement that
calls an already executing function. Recursion can also be indirect — function f can call g which calls h, and h could make a call back to f.
## recursive definition: A definition which
defines something in terms of itself. To be useful it must include base cases which are not recursive. In this way it differs from acircular definition. Recursive definitions often provide an elegant way to express complex
data structures, like a directory that can contain other directories, or a menu
that can contain other menus.
