🧾 Command Line Arguments in Java

Command Line Arguments allow users to pass input parameters to the program when it is executed, enabling dynamic behavior without changing code.

🧠 Concept

Java’s main() method accepts an array of String arguments:

public static void main(String[] args)
  • args holds the command line values as strings.
  • args[0], args[1], etc. refer to individual arguments.

🧪 Example

public class CmdArgs {
    public static void main(String[] args) {
        System.out.println("Number of arguments: " + args.length);
        for (int i = 0; i < args.length; i++) {
            System.out.println("Arg " + i + ": " + args[i]);
        }
    }
}

🔹 Running the program:

java CmdArgs Alice Bob

🔹 Output:

Number of arguments: 2
Arg 0: Alice
Arg 1: Bob

⚠️ Notes

  • All inputs are read as String. You must parse them (e.g., Integer.parseInt()) if needed.
  • Handle cases when arguments are missing to avoid ArrayIndexOutOfBoundsException.

🔗 Related Notes