Under Standing the HelloWorld Program
Class Declaration:
Class is the building block in Java, each
and every methods & variable exists within the class or object. (instance of
program is called object ). The public word specifies the accessibility
of the class. The visibility of the class or function can be public, private,
etc. The following code declares a new class "HelloWorld" with the
public accessibility:
public class HelloWorld {
The main Method:
The main method is the entry point in the Java program
and java program can't run without main method. JVM calls the main method of the
class. This method is always first thing that is executed in a java program.
Here is the main method:
public static void main(String[] args) {
......
.....
}
{ and is used to start the beginning of main block and
} ends the main block. Every thing in the main block is executed by the JVM.
The code:
System.out.println("Hello, World");
prints the "Hello World" on the console. The
above line calls the println method of System.out class.
The keyword static:
The keyword static indicates that the method is
a class method, which can be called without the requirement to
instantiate an object of the class. This is used by the Java interpreter to
launch the program by invoking the main method of the class identified in
the command to start the program.
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