1. By Divanshu Nandwani

2. • Software Industry
• Programing languages
• Problem with software industry
• What are design patterns?
• Different type of design patterns

3. • Development, maintenance, publication of software and
software services(such as training, documentation, and
consulting)
• Software as a service, or SaaS – 21st century trend to
reduce the piracy of software by providing everything on
web rather than client side installation
• Infrastructure software, including operating systems,
middleware, and databases
• Software that automates business processes

4. • A programming language is a notation for writing
programs, which are specifications of a computation or
algorithm
• A programming language's surface form is known as its
syntax
• The term Semantics refers to the meaning of languages,
as opposed to their form
• First programming language was designed in 1943, and
latest in 2011 (Dart)
• Assembly, Algorithmic, Functional, System, Logic,
Generic, Scripting and Object Oriented Programing
languages

5. • Very less success rate
• 1994 – 18%
• 2001 – 28%
• 2003 – 31%
• 2008
• Iterative – 71%
• Agile – 70%
• Traditional – 66%
• Ad-Hoc – 62%

6. • A design pattern is not a finished design that can be
transformed directly into code
• It is a description or template for how to solve a problem
that can be used in many different situations
• The design patterns may just be a sign of some missing
features of a given programming language
• Inappropriate use of patterns may unnecessarily increase
complexity
• There is no single, standard format for documenting
design patterns
• Erich Gamma, Richard Helm, Ralph Johnson and John
Vlissides is called “Gang of Four” or GoF

7. • Creational patterns
• Deal with object creation mechanisms
• Includes 9 design patterns like Singleton & Factory method
• Structural patterns
• Ease the design by identifying a simple way to realize
relationships between entities
• Includes 9 design patterns like Decorator & Façade

8. • Behavioral patterns
• Identify common communication patterns between objects
• Includes 15 design patterns like Chain of responsibility & Iterator
• Concurrency patterns
• Deal with multi-threaded programming paradigm
• Includes 14 design patterns like Thread pool & Lock