How to Use Command-Line Arguments in Java

You can pass values to a program using command-line arguments. To run the MySecondApp program and pass the values "value1" and "value2" as input, use the following command:

java com.company.lesson2.MySecondApp value1 value2

These values need to be received within the program. The main method helps us achieve this:

public static void main(String[] args)

This method takes an array of type String as a parameter: String[] args. This variable will contain the values we passed: "value1" and "value2".

In the following example, the main() method uses a for loop to iterate over the args array and print the command-line arguments. We will discuss for loops and arrays in more detail in future lessons.

package com.company.lesson2;

public class MySecondApp {
    public static void main(String[] args) {
        for (String str : args) {
            System.out.println("Argument = " + str);
        }
    }
}

Run the program using the following command:

java com.company.lesson2.MySecondApp value1 value2

Console output:

Argument = value1
Argument = value2