Object Oriented Programming

Front 1

class

Back 1

tell Ruby to make a new type of thing

Front 2

object

Back 2

Two meanings: the most basic type of thing, and any instance of some thing.

Front 3

instance

Back 3

What you get when you tell Ruby to create a class

Front 4

@

Back 4

Inside the functions in a class, @ is a variable for the instance/object being accessed.

Front 5

inheritance

Back 5

The concept that one class can inherit traits from another class, much like you and your parents.

Front 6

composition

Back 6

The concept that a class can be composed of other classes as parts, much like how a car has wheels.

Front 7

attribute

Back 7

A property classes have that are from composition and are usually variables.

Front 8

is-a

Back 8

A phrase to say that something inherits from another, as in a "salmon" is-a "fish."

Front 9

has-a

Back 9

A phrase to say that something is composed of other things or has a trait, as in "a salmon has-a mouth."

Front 10

class X(Y)

Back 10

"Make a class named X that is-a Y."

Front 11

class X(object): def initialize(J)

Back 11

"class X has-a initialize that takes a J parameter."

Front 12

class X(object): def M(J)

Back 12

"class X has-a function named M that takes a J parameter."

Front 13

foo = X()

Back 13

Set foo to an instance of class X

Front 14

foo.M(J)

Back 14

from foo get the M function and call it with parameter J

Front 15

foo.K = Q

Back 15

from foo get the K attribute and set it to Q