The char type and adding text to cells

In addition to color attributes, each cell can be associated with a single character. Java provides the type char to represent a single character or symbol from virtually all known alphabets or symbol sets in the world. Initially, we’ll limit ourselves to the character set on our keyboards, which is easiest to deal with. A char value in Java is surrounded by single quotes, unlike integer values. Since digits are part of our symbol set, a digit that is surrounded by single quotes is treated as a char value (We’ll find out later on what the difference is between the expressions 1+1 and ‘1’+’1’). Here are some char variable declarations:

char ch1 = ‘A’; // ch1 is the variable and ‘A’ is its value

char ch2 = ‘3’;

char ch3 = ‘@’;

char ch4 = ‘ ’; // yes, a space is a valid character

When you create a Board object, all of its cells have a character associated with them – the space. To change the character content of a cell, we use the method setChar, which requires 3 parameters: the x and y coordinates, and the character to associate with the cell (not surprising). Here’s a full program that will print out “CSC152”, one character per cell, on a 6x1 board colored yellow.

import java.awt.Color;

public class CSC152Board

{

public static void main(String[] args)

{

Board b = new Board(6,1);

b.fillCells(0, 0, 5, 0, Color.yellow);

b.setChar(0, 0, 'C');

b.setChar(1, 0, 'S');

b.setChar(2, 0, 'C');

b.setChar(3, 0, '1');

b.setChar(4, 0, '5');

b.setChar(5, 0, '2');

}

}