CIS 3020 Part 9

Command Line Arguments

• When you execute a Java program, you can provide values directly to the program
• These values are called "command line arguments" since they are in the command to execute your program:

java Print2CLArgs 123 hello

class Print2CLArgs {
  public static void main (String[] arg) {
    ...
    System.out.println(arg[0]);
    System.out.println(arg[1]);
    ...
  }
}

• Remember: the command line arguments are strings
• Suppose we execute: java PrintSum 3 5
• And PrintSum contains:

System.out.println(arg[0] + arg[1]);

• What will be output?

35

• What you need to write is:

int i1 = Integer.parseInt(arg[0]);
int i2 = Integer.parseInt(arg[1]);
System.out.println(i1 + i2);