What is "String args[]"? parameter in main method Java

Question

I'm just beginning to write programs in Java. What does the following Java code mean?

public static void main(String[] args) 

• What is String[] args?

• When would you use these args?

Source code and/or examples are preferred over abstract explanations

Answer 1

In Java args contains the supplied command-line arguments as an array of String objects.

In other words, if you run your program in your terminal as :

C:/ java MyProgram one two 

then args will contain ["one", "two"].

If you wanted to output the contents of args, you can just loop through them like this...

public class ArgumentExample {     public static void main(String[] args) {         for(int i = 0; i < args.length; i++) {             System.out.println(args[i]);         }     } } 

The program will print in the terminal:

C:/ java MyProgram one two one two      C:/ 

Answer 2

Those are for command-line arguments in Java.

In other words, if you run

java MyProgram one two

Then args contains:

[ "one", "two" ]

public static void main(String [] args) {     String one = args[0]; //=="one"     String two = args[1]; //=="two" } 

The reason for this is to configure your application to run a particular way or provide it with some piece of information it needs.

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If you are new to Java, I highly recommend reading through the official Oracle's Java™ Tutorials.