Public :The main method
must be declared as public because it means it is visible to all(spatially for
JVM) and can be called from anywhere.
Static:
is a special [optional] keyword that indicates that this method can be called
without creating an instance of this class means no need to create an object to
invoke the main method and It is used with main().
void: is the return
type of this method, indicating that this method doesn't return anything.
main: is the name of
a function. main() is special because it is the start of the program.
String[] args :
is a single parameter for the method. String[] is the type of the
parameter, indicating an array of Strings. args is the name of the
parameter. Parameters must be named.
Note:String[] args
and String args[] Both of them are absolutely the same and both create an array
(reserves a place in memory)with no size and name args.
Example:
public class HelloWorld {
public static void
main(String[] args) {
System.out.println("Hello, World");
}
}
Steps to execute the java program.
Step1:
Save the above code in java file
Helloworld.java
public
class HelloWorld {
public static void
main(String[] args) {
System.out.println("Hello, World");
}
}
Step2:
Compiling a Java program : Open the command prompt or (terminal for linux)
just execute below command
javac HelloWorld.java
Step3:
Executing a Java program: Once you compile your program, you can run
it. This is the exciting part, where the computer follows your instructions. To
run the HelloWorld program, type the following at the terminal:
java HelloWorld
