Variables or expressions as parameters

Just as values can be parameters to methods, it’s also possible to use variable names, and even expressions, as parameters. An example of where this would be needed is a program that prompts the user to enter the coordinate of the cell that he or she wishes to color red. Here’s the full program:

import java.util.Scanner;

import java.awt.Color;

public class ColorACell

{

public static void main(String[] args)

{

// create Board object

Board b = new Board(10, 10);

// create Scanner object

Scanner input = new Scanner(System.in);

// obtain input from user and store in variables

System.out.print("Enter the x-coordinate of the cell you'd

like to color (max is 9): ");

int xCoord = input.nextInt();

System.out.print("Enter its y-coordinate (max is 9): ");

int yCoord = input.nextInt();

// use the variables as parameters

b.fillCell(xCoord, yCoord, Color.red);

}

}

If you’re running this program in DrJava, you will find the prompt to enter the coordinate values in the Interactions pane.