Command Line Arguments

In this tutorial, we are going to discuss Command Line Arguments in Java. Command-line arguments are parameters passed to a program when it is executed via the command line or terminal. In Java, command-line arguments are provided to the main method as an array of strings.

The main object of command line arguments are we can customize the behavior of main.

java Test a b c

Here a = arg[0];
b = arg[1];
c = arg[2];
args.length = 3;

package com.ashok.test;

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

Output

java Test // Nothing Display
java Test A B // A B

Within the main() command line arguments are available in string form.

package com.ashok.test;

public class Test {
   public static void main(String args[]) {
      System.out.print(args[0]+args[1]]);
   }
}

Output

java Test 10 20 // 1020

Space is the separator between command line arguments, if the command line arguments itself contain space then we should enclose with in double quotes.

package com.ashok.test;

public class Test {
   public static void main(String args[]) {
      System.out.print(args[0]);
   }
}

Output

java Test "Ashok Kumar" // Ashok Kumar

package com.ashok.test;

public class Test {
   public static void main(String args[]) {
      String argh = {'A','B'};
      args = argh;
      for(String s : args) {
         System.out.println(s);
      }
   }
}

java Test X Y
O/P A B

java Test X Y Z
O/P A B

java Test
O/P A B

Note

The maximum allowed number of command line arguments is 2147483647 which is maximum size of integer data type and minimum is 0.

Command-line arguments are useful for passing input parameters, configuration options, file paths, or any other data to a Java program when it is executed.

That’s all about Command line arguments in Java. If you have any queries or feedback, please write us at contact@waytoeasylearn.com. Enjoy learning, Enjoy Java.!!

Command Line Arguments