what are command line arguments in java

Command line arguments in Java are inputs you pass to a program when you start it from the terminal or command prompt. They are received by the main method as a String[] args array, so each argument is available as a separate string.

Quick Scoop

If you run a Java program like this:

bash

java MyApp hello 10 world

then hello, 10, and world are the command line arguments. Inside the program, you can read them with args[0], args[1], and args[2].

How They Work

• The JVM puts everything after the class name into the args array.

• You can check how many arguments were passed with args.length.

• Arguments are separated by spaces, and quoted text counts as one argument.

Example

java

class Main {
    public static void main(String[] args) {
        System.out.println("First arg: " + args[0]);
        System.out.println("Total args: " + args.length);
    }
}

If you run:

bash

java Main Java Rocks

the output would be:

bash

First arg: Java
Total args: 2

Important Note

All command line arguments arrive as strings, even if they look like numbers. If you need an integer or double, you must convert it in your code.

If you want, I can also show you how to use command line arguments in a complete Java program.