1_oop

OOP

Sections

1. Abstraction

   1. Definition
   2. Abstraction Example
   3. Abstraction 2 types

2. Encapsulation

   1. difference between abstraction && encapsulation

3. Inheritance

   1. Forms of Inheritance in Object Oriented Programming
      1. Single inheritance
      2. Multiple Inheritance
      3. Multi-level
      4. Hierarchical inheritance
      5. Hybrid Inheritance

4. Polymorphism

   1. (2) types of polymorphism:

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Abstraction

- hiding unnecessary details and data from the user.
- show what functionality available to use.

Definition

• Its main goal is to handle complexity
  • by hiding unnecessary details and data from the user.
• focus on what functionality available to use
• That enables the user to implement more complex logic on top of the provided abstraction without understanding or even thinking about all the hidden complexity.

example: the coffee machine

• You need to know how to use your coffee machine to make coffee.

• You need to provide 1-water and 2-coffee beans, switch it on and 3-select the kind of coffee you want to get.

• The thing you don’t need to know is how the coffee machine is working internally.

Abstraction two types.

source: https://www.journaldev.com/33191/what-is-abstraction-in-oops

1. Data Abstraction (private data)
2. Process Abstraction (private methods)

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Encapsulation

- bundling(wrapping) data and methods that work on that data within a single unit

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Difference between abstraction && encapsulation

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Inheritance

- It is a mechanism where you can to derive a class from another class for a hierarchy of classes 
- that share a set of attributes and methods.

Forms of Inheritance in Object Oriented Programming

source: https://www.guru99.com/java-class-inheritance.html

type	Definition
1. Single inheritance	This is a form of inheritance in which a class inherits only one parent class
2. Multiple Inheritance	An inheritance becomes multiple inheritances when a class inherits more than one parent class. ""NOt Exist In dart""
3. Multi-level	For example, a class_1 is inherited by a class_2 and this class_2 also gets inherited by class_3 and this process goes on. This is known as multi-level inheritance.
4. Hierarchical inheritance	In this, various Child classes inherit a single Parent class. The example given in the introduction of the inheritance is an example of Hierarchical inheritance since classes BMW and Audi inherit class Car.
5. Hybrid Inheritance	When there is a combination of more than one form of inheritance, it is known as hybrid inheritance.

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Polymorphism

 - Many Form >> perform a single action in different ways
 - it occurs when we have many classes that are related to each other by inheritance.
 - Polymorphism is the ability of an object to take on many forms. 
 - it describes the concept that you can access objects of different types through the same interface. 
 - Each type can provide its own independent implementation of this interface.

2 types of polymorphism:

1. static or compile-time
2. dynamic

### `Static`: 
 - can determine which method will run in the compiling time
 - do the same operation in same class
 - Overload
 - NO overloading in dart

### `Dynamic`: 
 - can determine which method will run in the run time
 - same operation in different classes
 - Override