Main Method is Public Static in Java

Why main method is public static in Java

Main method in Java is Java  is the first programming method a Java programmer knows when he starts learning Java programming language.have you ever thought about why main method in Java is public, static and void, void , of-course Yes, since most of us first learn C and C++ than we move to Java in our programming path we familiar with main method but in Java main method is slightly different it doesn't return any value like in C it returns int, main method is public static and void Why  !n this post we will try to find answer of these "uestions and have an idea of one of the most popular "uestions in Java why main method is declared #tatic.

What is main method in Java? $ain method in Java Java is entry point for any core Java program. %emember %emember we are not talking about #ervlet, $!&let or any other container managed Java program where life cycle methods are provided to control the eecution. !n core Java program, eecution starts from main method when you type  (ava main-class-name, J)$ search for public static void main(String args[])  method in that class and if it doesn't find that method it throws error NoSuchMethodErrormain NoSuchMethodErrormain and  and terminates. Signature o! main method in Java $ain method has to strictly follow its synta* otherwise J)$ will not be able to locate it and your program will not run. ere is the eact signature of main method public static void main(String args[]) his signature signature is classic classic signature signature and there from start of Java Java but with introducti introduction on of variable argument or varargs in Java  Java  you can also declare main method in Java using varargs synta as shown in below eample public static void main(String""" args) %emember %emember varargs version of (ava main method will only work in Java /. or later version. 0part from public, public, static static and void there are certain keywords keywords like final, synchroni synchroni1ed 1ed and strictfp strictfp which are permitted in signature of (ava main method.

Why main method is static in Java 2ow come to the main point "Why main method is static in Java" , there are "uite a few reasons around but here are few reasons which make sense to me /. #ince main method is static Java virtual $achine can call it without creating any instance of class which contains main method. 3. #ince C and C++ also has similar main method which serves as entry point for program eecution, following that convention will only help Java. 4. !f main method were not declared static than J)$ has to create instance of main Class and since constructor can be overloaded and can have arguments there would not be any certain and consistent way for J#M to !ind main method in Java. Java. 5. 0nything which is declared in class in Java comes Java comes under reference type and re"uires ob(ect to be created before using them but static method and static data are loaded into separate memory inside J)$ called contet which is created when a class is loaded. !f main method is static than it will be loaded in J)$ contet and are available to eecution.

$hy main mehtod is public in Java Java specifies several access modifiers e.g. private, protected and public. 0ny method or variable which is declared public in Java can be accessible from outside of that class. #ince main method is public in Java, J)$ can easily access and eecute it. $hy main method is void in Java #ince main method in Java is not supposed to return any value, its made void which simply means main is not returning anything. Summary /. $ain method must be declared public, static and void in Java otherwise J)$ will not able to run Java program. 3. J)$ throws NoSuchMethodE%ceptionmain if it doesn't find main method of predefined signature in class which is provided to Java command. 6.g. if you run (ava elloworld than J)$ will search for public static void main #tring args789 method in ello:orld.class file. 4. $ain method is entry point for any Core Java program. 6ecution starts from main method. 5. $ain method is run by a special thread called ;main; thread in Java. Your Java program will be running until your main thread is running or any non-daemon thread spawned from main method is running. . :hen you see &E%ception in 'hread main e.g. E%ception in 'hread main Java"lang"NullointerE%ception  it means 6ception is thrown inside main thread. <. You can declare main method using varargs synta from Java /. onwards e.g. public static void main(String""" args) =. 0part from static, void and public you can use final, synchroni1ed and strictfp modifier in signature of main method in J ava. >. $ain method in Java can be overloaded like any other method in Java but J)$ will only call main method with specified signature specified above. ?. You can use throws clause in signature of main method and can throw any checked or unchecked 6ception. /@. #tatic initiali1er block is eecuted even before J)$ calls main method. hey are eecuted when a Class is loaded into $emory by J)$.