JAVA prompt

Permanent Generation (which is “Perm” in PermSize) The permanent generation is used to hold reflective of the VM itself such as class objects and method objects. These reflective objects are allocated directly into the permanent generation, and it is sized independently from the other generations. Generally, sizing of this generation can be ignored because the default size is adequate. However, programs that load many classes may need a larger permanent generation. PermSize is additional separate heap space to the -Xmx value set by the user. The section of the heap reserved for the permanent generation holds all of the reflective data for the JVM. You should adjust the size accordingly if your application dynamically load and unload a lot of classes in order to optimize the performance. By default, MaxPermSize will be 32mb for -client and 64mb for -server. However, if you do not set both PermSize and MaxPermSize, the overall heap will not increase unless it is needed. When you set both...

1. Abstraction Abstraction helps to hide the non essential features from the user and makes the application user friendly. Eg. Take your mobile phone. You are having buttons and know the purpose but no need to understand how it prints number on the screen when it is pressed. 2. Encapsulation It bundles the code into a single unit which makes the code very easy to handle. Eg. Take computer keyboard. All the buttons have been enclosed. 3. Inheritance It helps to inherit the superclass properties to subclasses. Eg. Father - Son relationship. 4. Polymorphism A entity which behaves differntly at different places. Eg. A person behaves as a good husband in family. He behaves as a good employee at company. He also behaves as a good citizen in public

There are four main object oriented concepts in java. 1. Abstraction 2. Encapsultion 3. Inheritance 4. Polymorphism