What is System, out, println in System.out.println() in Java…

This tutorial is to explain what System.out.println is and how it works. How many times have we used System.out.println till now? It is one of the most number of times compiled statement in the history of java. We also call System.out.println  as SOP in short form.

·         System is a built-in class present in java.lang package. This class has a final modifier, which means that, it cannot be inherited by other classes. It contains pre-defined methods and fields, which provides facilities like standard input, output, etc.

·         out is a static final field ie variable in System class which is of the type PrintStream “a built-in class, contains methods to print the different data values”. static fields and methods must be accessed by using the class name, so ( System.out ).

·         out here denotes the reference variable of the type PrintStream class.

·         println() is a public method in PrintStream class to print the data values. Hence to access a method in PrintStream class, we use out.println(), “as non static methods and fields can only be accessed by using the refrence varialble”

         Eg.

                   System.out.print("Hello World");

                      System.out.print("My name is" + foo);

                      System.out.print("Sum of " + a + "and " + b + "is " + c);

                     System.out.print("Total USD is " + usd);

                                                  We will give you more information about system.out.println() later...