Feature of JAVA Programming Language

Feature of JAVA Programming Language

• Here we list the basic features that make Java a powerful and popular programming language:

• Platform Independence

• The Write-Once-Run-Anywhere ideal has not been achieved (tuning for different platforms usually required), but closer than with other languages.

• Object Oriented

• Object oriented throughout - no coding outside of class definitions, including main().
• An extensive class library available in the core language packages.

• Compiler/Interpreter Combo

• Code is compiled to bytecodes that are interpreted by a Java virtual machines (JVM) .
• This provides portability to any machine for which a virtual machine has been written.
• The two steps of compilation and interpretation allow for extensive code checking and improved security.

• Robust

• Exception handling built-in, strong type checking (that is, all data must be declared an explicit type), local variables must be initialized. 

• Several dangerous features of C & C++ eliminated:

• No memory pointers 
• No preprocessor
• Array index limit checking

• Automatic Memory Management

• Automatic garbage collection - memory management handled by JVM.

• Security

• No memory pointers
• Programs runs inside the virtual machine sandbox.
• Array index limit checking
• Code pathologies reduced by
• bytecode verifier - checks classes after loading
• class loader - confines objects to unique namespaces. Prevents loading        a hacked "java.lang.SecurityManager" class, for example.
• security manager - determines what resources a class can access such as reading and writing to the local disk.

• Dynamic Binding

• The linking of data and methods to where they are located, is done at run-time.
• New classes can be loaded while a program is running. Linking is done on the fly.
• Even if libraries are recompiled, there is no need to recompile code that uses classes in those libraries.
  
  This differs from C++, which uses static binding. This can result in fragile(easily broken) classes for cases where linked code is changed and memory pointers then point to the wrong addresses.

• Good Performance

• Interpretation of bytecodes slowed performance in early versions, but advanced virtual machines with adaptive and just-in-time compilation and other techniques now typically provide performance up to 50% to 100% the speed of C++ programs. 

• Threading

• Lightweight processes, called threads, can easily be spun (turned) off to perform multiprocessing.
• Can take advantage of multiprocessors where available
• Great for multimedia displays.

• Built-in Networking

• Java was designed with networking in mind and comes with many classes to develop sophisticated Internet communications.