Diamond.java

Below is the syntax highlighted version of Diamond.java from §1.3 Conditionals and Loops.

/*************************************************************************
 *  Compilation:  javac Diamond.java
 *  Execution:    java Diamond N
 *  
 *  Prints out a 2N+1-by-2N+1 diamond like the one below.
 *
 *  % java Diamond 4
 *  . . . . * . . . . 
 *  . . . * * * . . . 
 *  . . * * * * * . . 
 *  . * * * * * * * . 
 *  * * * * * * * * * 
 *  . * * * * * * * . 
 *  . . * * * * * . . 
 *  . . . * * * . . . 
 *  . . . . * . . . . 
 *
 *************************************************************************/

public class Diamond {

    public static void main(String[] args) { 
        int N = Integer.parseInt(args[0]);

        for (int i = -N; i <= N; i++) {
            for (int j = -N; j <= N; j++) {
                if (Math.abs(i) + Math.abs(j) <= N) System.out.print("* ");
                else                                System.out.print(". ");
            }
            System.out.println();
        }
    }
}