ch06/triangle1/Triangle.java
 /**
 This class describes triangle objects that can be displayed
 as shapes like this:
 []
 [][]
 [][][].
*/
 public class Triangle
 {
 /**
 Constructs a triangle.
 @param aWidth the number of [] in the last row of the triangle
 */
 public Triangle(int aWidth)
 {
 width = aWidth;
 }

 /**
 Computes a string representing the triangle.
 @return a string consisting of [] and newline characters
 */
 public String toString()
 {
 String r = "";
 for (int i = 1; i <= width; i++)
 {
 // Make triangle row
 for (int j = 1; j <= i; j++)
 r = r + "[]";
r = r + "\n";
 }
 return r;
 }

private int width;
 }