Creational-Design-Patterns-Note.txt

					Creational
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			How do you want to create objects?
				=> These design patterns are all about class instantiation or object creation. 
				These patterns can be further categorized into Class-creational patterns and object-creational patterns. 
				While class-creation patterns use inheritance effectively in the instantiation process, object-creation patterns use delegation effectively to get the job done.
			

1. Prototype: A fully initialized instance to be copied or cloned
		Example: initial status of chess game
		java.lang.Object#clone()

2. Builder - Separates the construction of a complex object from its representation 
			so that the same construction process can create different representations
			
		Example: Kitchen is a Factory, Chef is a Builder where waiter tells to the chef "pizza with cheese, onion". 
				Here chef exposed attributes but hidden implementation.

		java.lang.StringBuilder
			
3. Singleton - A class of which only a single instance can exist
	
		Example: President of a country

		java.lang.Runtime#getRuntime()

4. Factory Method - Creates an instance of several derived classes.

		Example: In an organization, HR works as a factory method. 
				Here development team request type of resource needs to HR. 
				Based on request type, HR provides resource to Development team.

		java.util.Calendar#getInstance()
				
5. Abstract Factory - Creates an instance of several families of classes
				
		Example: HP, Samsung, and Dell laptops are using Intel and AMD processor.

		javax.xml.parsers.DocumentBuilderFactory#newInstance()