Java Questions

new ClassName();

This expression creates object in heap area and returns that obj address. Here JVM creates object but JVM does not returns object original address. JVM returns duplicate address, duplicate address is also called as hashcode. 

This is a keyword and used as reference to Current object address in java. 

It means by using which object the method is called that object hashcode is stored inside the 'this'.

JAR files are java's version of ZIP files. In fact, JAR uses the ZIP file format.

uses:

- to compress a number of . class files into one file

- to make a java executable JAR file.

By using method.

The method used to set the data is called setter method.

Overriding means changing behavior of methods of base class in derive class by overriding the base class methods. If class A is a base class with method ’calculate’ and class B inherits class A, thus derives method ’calculate’ of class A. The behavior of ’calculate’ in class B can be changed by overriding it.

Variables declared within a method are local variables. Variables declared within the class are member variables.  Variables declared within the class with static modifier are class variables 

A method declared as final can't be overridden. A sub-class can't have the same method signature with a different implementation.

:: is the scope resolution operator. When local variable and global variable are having same name, local variable gets the priority. C++ allows flexibility of accessing both the variables through a scope resolution operator