Object Orientated Programming - A Level Computer Science

Classes & Instances

A class is a blueprint/blueprint for an object.

Object / Instance
Objects are what the blueprint makes.
An instance is an individual object.
Objects & Instances are widely used interchangeably.
A blueprint for a house design is like a class description. All the houses built from that blueprint are objects of that class. A given house is an instance.

Properties / Attributes

Methods

This feature of OOP is where a subclass inherits a feature (either a method or attribute) from the parent class.

class MotorVehicle:
    def __init__(self):
        self.wheels = 4

class Car(MotorVehicle):
    def __init__(self):
        MotorVehicle.__init__()

car = Car()
print(car.wheels)
#Here Car inherits the wheels attribute from the parent class.

Winter 19 Paper 41 – Question 1C