Best Java Interview Questions and Answer Preparation Resources
Java is a programming language used in building applications. It's a class-based, object oriented programming language which functions on "write one time, run anywhere principle". The java coding once done can run on any platform and don't require recompilation. It is currently the most popular programming language and therefore, one can fairly guess the demand that these professionals enjoy.Java was first introduced by Sun Microsystem in 1995. It was developed to run most independently with few implementation dependencies. It has adopted most of its syntax from C and C++, which is often regarded as basics of programming language.
Java is used to create complete applications that may possibly run on a single computer or be distributed among servers and clients in a network. It is also used to build a small application module or applet for use as part of a webpage ans webserver.
Substitutability means, the type of the variable does not have to match with the type of the value assigned to that variable. Substitutability cannot be achieved in conventional languages in C and C++, but can be achieved in Object Oriented languages like Java.