2.2 Testing the Rect Class

Example 2-2 is a standalone program named RectTest that puts the Rect class of Example 2-1 through its paces. Note the use of the new keyword and the Rect( ) constructor to create new Rect objects. The program uses the . operator to invoke methods of the Rect objects and to access their fields. The test program also relies implicitly on the toString( ) method of Rect when it uses the string concatenation operator (+) to create strings to be displayed to the user.

Example 2-2. RectTest.java
package je3.classes; /** This class demonstrates how you might use the Rect class */ public class RectTest {     public static void main(String[  ] args) {         Rect r1 = new Rect(1, 1, 4, 4);    // Create Rect objects         Rect r2 = new Rect(2, 3, 5, 6);         Rect u = r1.union(r2);             // Invoke Rect methods         Rect i = r2.intersection(r1);                  if (u.isInside(r2.x1, r2.y1))   // Use Rect fields and invoke a method             System.out.println("(" + r2.x1 + "," + r2.y1 +                                ") is inside the union");                  // These lines implicitly call the Rect.toString( ) method         System.out.println(r1 + " union " + r2 + " = " + u);         System.out.println(r1 + " intersect " + r2 + " = " + i);     } }


Java Examples in a Nutshell
Java Examples in a Nutshell, 3rd Edition
ISBN: 0596006209
EAN: 2147483647
Year: 2003
Pages: 285

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