1. Create a new project in Eclipse names Flags and create a class named Flag. Be certain you create a main method.
2. Add the following code to main.

boolean evenFlag = (Integer.parseInt(args[0]) %2 == 0);
if(evenFlag) {
  System.out.println("arg[0] was even");
}
else {
  System.out.println("arg[0] was odd");
}

The completed class appears as follows.

public class Flag {
  public static void main(String[] args) {
    boolean evenFlag = (Integer.parseInt(args[0]) %2 == 0);
    if(evenFlag) {
      System.out.println("arg[0] was even");
    }
    else {
      System.out.println("arg[0] was odd");
    }
  }
}

3. Click the run button and note the error that occurs.

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
	at Flag.main(Flag.java:5)

4. The error is due to no parameter having been passed to the program. To pass a parameter in Eclipse you must do the following. First, from the Run menu, select Run Configurations.
5. Click the Arguments tab and enter three into the program arguments text area.
6. Click the Run button and you should see the following results in the Console tab.
7. You can modify the value passed to the program by returning to the saved run configuration. Note that here the configuration was named Flag.
8. Change the Program arguments to six, click Run, and note the printed results change.

arg[0] was even