Explanation of String args and static in public static void main String args

Question

How can you explain very well  to a beginner  the meaning of String args   and the use of static in the following excerpt   class FirstApp       public static void main String   args

User · Answer

public   it is a access specifier that means it will be accessed by publically  static   it is access modifier that means when the java program is load then it will create the space in memory automatically  void   it is a return type i e it does not return any value  main     it is a method or a function name  string args     its a command line argument it is a collection of variables in the string format

User · Answer

public static void main string    args    public -its the access specifier means from every where we can access it  static -access modifier means we can call this method directly using a class name without creating an object of it  void- its the return type  main- method name string    args - it accepts only string type of argument    and stores it in a string array

User · Answer

To keep beginner attitude you can explain that all the command line is automaticaly splite in a array fo String  the String      For static you have to explain  that it not a field like another   it is unique in the JVM even if you have thousand instances of the class  So main is static  because it is the only way to find it  linked in its own class  in a jar       after you look at coding  and your job begin

User · Answer

I would break up public static void main String args     in parts   public It means that you can call this method from outside of the class you are currently in  This is necessary because this method is being called by the Java runtime system which is not located in your current class     static When the JVM makes call to the main method there is no object existing for the class being called therefore it has to have static method to allow invocation from class     void Java is platform independent language and if it will return some value then the value may mean different things to different platforms  Also there are other ways to exit the program on a multithreaded system  Detailed explaination     main It s just the name of method  This name is fixed and as it s called by the JVM as entry point for an application     String args   These are the arguments of type String that your Java application accepts when you run it

User · Answer

The normal usage of static is to access the function directly with out any object creation  Same as in java main we could not create any object for that class to invoke the main method  It will execute automatically  If we want to execute manually we can call by using main   inside the class and ClassName main from outside the class

User · Answer

I just thought I d chip in on this one  It s been answered perfectly well by others though   The full main method declaration should be     public static void main final String   args  throws Exception         The args are declared final because technically they should not be altered  They are console parameters given by the user   You should usually specify that main throws Exception so that stack traces can be echoed to console easily without needing to do e printStackTrace   etc   As for Array Syntax  I prefer it this way  I suppose that it s a little bit like the difference between french and english  In English it s  a black car   in french it s  a car black   Which is the important noun  car  or black   I don t like this sort of thing    String blah           What s important here is that it s a String array  so it should be  String   blah         blah is just a name  I personally think it s a bit of a mistake in Java that arrays can sometimes be declared in that manner

User · Answer

If I were explaining this to someone I d say we ll get to it later for now you need to know that the way to run your program is to use    public static void main String   args                        Assuming he she knows what an array is  I d say the args is an argument array and you can show some cool examples   Then after you ve gone a bit about Java JVM and that stuff  you d get to modifiers eventually to static and public as well   Then you can spend some time talking about meaning of these IMHO   You could mention other  cool  stuff such as varargs that you can use this in later versions of Java   public static void main String    args

User · Answer

I would point a beginner to the Wiki article on the Main function  then supplement it with this    Java only starts running a program with the specific public static void main String   args  signature  and one can think of a signature like their own name - it s how Java can tell the difference between someone else s main   and the one true main    String   args is a collection of Strings  separated by a space  which can be typed into the program on the terminal   More times than not  the beginner isn t going to use this variable  but it s always there just in case

[java] Explanation of 'String args[]' and static in 'public static void main(String[] args)'

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