Open Close Principle is an Object Oriented Design principle. It is first introduced by Betrand Meyer in 1988. He says “Software entities (Class, module, function etc.) should be open for extension, but closed for modification”. An entity is “Open for extension” means that its behavior can be extended to accommodate new demand. The entity is
What is Abstract Class? Abstract class is a class that has no direct instances, but its descendants may have direct instances. An abstract class is a class that can contain abstract members, although it is not required. But any class that contains abstract member must be abstract. An abstract class can also contain non-abstract members.
Step 1: Press Windows + R to get “run” window and type “powercfg.cpl” Press enter. Now you will be lead to “Power options” window. Step 2: Click on “Choose what power buttons do”. Step 3: Click on “Change settings that are currently unavailable” Now some controls are enabled. Scroll down, there you can able to
Design Pattern Design pattern is a solution of known problems. These are strategies of solving commonly occurring problems. A design pattern is not a finish design. It is like a template to solve a problem. Singleton Design Pattern Singleton is a software design pattern. It is restrict to create object more than once. This is