Programming in Objective-C, Sixth Edition

Exercises

1. What will happen if you insert the message expression

[compResult reduce];

into Program 9.1 after the addition is performed? Try it and see.

2. Can the id variable dataValue, as defined in Program 9.2, be assigned a Rectangle object as you defined it in Chapter 8? That is, is the statement

Click here to view code image

dataValue = [[Rectangle alloc] init];

valid? Why or why not?

3. Add a print method to your XYPoint class defined in Chapter 8. Have it display the point in the format (x, y). Then modify Program 9.2 to incorporate an XYPoint object. Have the modified program create an XYPoint object, set its value, assign it to the id variable dataValue, and then display its value.

4. Based on the discussions about argument and return ...