Command Line Arguments
- You can pass information into a program when you run it. This is accomplished by passing command-line arguments to main( ).
- A command-line argument is the information that directly follows the program's name on the command line when it is executed.
- The command-line arguments are stored as strings in the String array passed to main( ). You have to use the index for accessing the argument which starts from 0 as given below program.
- Here we pass two numbers using command line and add these two numbers into sum variable and display it.
- The Integer.parseInt(args[0]) uses parseInt( ) method of Integer wrapper class which converts string object to primitive integer type. Note that when you pass command line arguments they are collected in a string array.
- The program source code is given below:
PROGRAM
class CmdLineArgDemo {
public static void main(String[] args) {
int no1 = Integer.parseInt(args[0]);
int no2 = Integer.parseInt(args[1]);
int sum = no1 + no2;
System.out.println("Addition of two numbers is "+sum);
}
}
The output of the code is given below:
OUTPUT
C:\>javac CmdLineArgDemo.java C:\>java CmdLineArgDemo 10 21 Addition of two numbers is 31
Here 10 & 21 are called command line arguments which are passed to java interpreter while running the program.