Creational design patterns

Factory

Provides an interface to create objects. Rather than creating new objects using new keyword, we ask the factory to create and return them for us. 

Factory in JavaScript : method1 (addyosmani) and method2 (carldanley)

Builder

http://www.oodesign.com/builder-pattern.html

Lazy initialization

Creation is deferred until it is first used. Useful for complex objects. 

C# : http://msdn.microsoft.com/en-us/library/dd997286%28v=vs.110%29.aspx

Object pool

Useful when cost of initializing a class instance is very high.  Therefore when requester requires an instance, he can get one of already created instance.

Prototype




Singleton 

http://stackoverflow.com/questions/327955/does-functional-programming-replace-gof-design-patterns?rq=1

Read More

Introduction to Testing

Testing is a mechanism we use to evaluate whether the software we are developing satisfies the specified requirements. Testing is a very broad subject. Here we'll just look in to some high level overview of what it is.

Types of testing

• Manual testing
• Takes the role of an end user and checks for unexpected behavior 
• There are few levels like unit testing, integration testing, system testing and user acceptance testing
• Uses test plan, test cases or test scenarios to test
• Automation testing
• Also known as Test Automation
• Testers writes scripts and use other software to do testing
• Rerun test scenarios quickly and repeatedly
• Use tools like Selenium, VS Test Professional, IBM Rationale function tester

Testing methods

• Black box 
• Without having any knowledge of interior workings of the application (UI level)
• White box
• Detailed investigation of internal logic
• Grey box
• Testing with limited knowledg

Read More