CS12, Lab 3

Week of April 15 – 19

Topics:

· Constructors

· Overloading (two functions with the same name)

· Methods calling other methods.

· Memberwise copy

· More practice with using classes

· Default parameters

You will be modifying the files from Lab 2.

To do:

· Copy the files dice.h and dice.cpp from Lab 2 into a new folder.

· Add a constructor with one parameter that allows the user to specify the number of sides at declaration. When setting the number of sides, the constructor should use the method setNumSides(int).

· Add a new roll function that takes one parameter. The call roll(x) should return a number between 1 and x, inclusive. In other words, roll(x) rolls a Dice object with x sides. To achieve this, the method should first change the number of sides of the object to x (by calling the appropriate method), then roll the object (by calling roll()).

· In your main program (lab3main.cpp),

1. Create a Dice object with 10 sides (in one statement).

2. Verify that the number of sides is 10 by outputting the value retuned from getNumSides().

3. Roll the object 3 times, printing the results of the rolls.

3. Roll the object again, this time with 5 sides, using the new roll(int) method

4. Check that the number of sides has changed by outputting the value retuned from getNumSides().

5. Output the number of rolls that the object has made (should be 4).

6. Declare a second Dice object using the default constructor.

7. Output the number of sides and the number of rolls (should be 6 and 0).

8. Assign to this object the value of the first object declared.

9. Repeat step 7 (values should be 5 and 4 now).

Extra credit

Experiment:

1. What happens when you compile a program with two constructors, one that has no parameters and another with one parameter with a default value? Use an empty main(). Does your program compile?

2. If the program does compile, try declaring in main() an object with no parameters. Does your program compile now?

3. If the program compiles and runs, how can you check which constructor gets called if no argument is specified?