Benefits of design pattern?

Problem statement: what are the benefits of design pattern?

1. code re-usability
2. loosely coupled
3. reduce total cost
4. highly maintainability

what is design pattern?

Problem statement: what is design pattern?

1. A well defined solution to a common problem
2. International standard approach 
3. template / approach
4. language independent(java, .net)

why do we need design pattern?

Problem statement: why do we need design pattern?

• Solution of commonly occurring problem

1. how to create a class properly
2. how to instantiate an object
3. how to interact between object
4. how to write loosely coupled code
5. how to write reusable code

Best Practices of Design Pattern?

Problem statement: what are the best practices of design pattern?

1. keep it simple
2. focus on loosely coupled code
3. design first, code later

Types of design pattern?

Problem statement: what are the types of design pattern?

• Types of Design Pattern?

1. Structural: Adapter, Facade
2. Creational: Singleton, Factory
3. Behavioral: Iterator, Observer, Stragegy

Structural: deals with structure of class and it is made of variable & methods
Creational: deals with how to instantiate an object
Behavioral: one class interact with other

• Enterprise level design pattern?

1. MVC - model view controller
2. DI - Dependency Injection
3. DAO - Data Access Object
4. DTO - Data Transfer Object