3. Classes Quiz

You may not use any notes or old classes to help you. Please write your answers on paper. These questions are not intended to be programmed on a computer.

HarmonicAdder

The HarmonicAdder is not in GridWorld, it is just a class. Make it normally, but do not try to put it in the grid. A HarmonicAdder begins at a given initial x-coordinate on the number line.

• The report() method returns the current location.
• The hut() method updates the location by adding 1/n on move number n.

HarmonicAdder a = new HarmonicAdder(5.2);
a.hut();
a.report();  // 5.2 + 1/1 = 6.2
a.hut();
a.report();  // 6.2 + 1/2 = 6.7
a.hut();
a.hut();
a.report();  // 6.7 + 1/3 + 1/4 = 7.28333...
// 

The System.out.println(value); method will let you print your location in a visible way.

DashBug

The DashBug is in GridWorld. (Starter code.)

1. The DashBug walks steps times with the ordinary Bug act() method, and then walks for two steps using the move() method. The cycle is repeated cycle times.

2. A DashBug made without specifying the number of steps or cycles should repeat 3 steps in two cycles.

When the bug is done moving it should be stationary.

The constructors should let the code below work:

int steps = 4;
int cycle = 3;
Bug c = new DashBug(steps, cycle);
Bug d = new DashBug();
world.add(new Location(8,3), c);
world.add(new Location(8,4), d);
[...]

DashBugRunner on GitHub.

Details:

• DashBug must have all actions driven by the act() method.

• The bug c = new DashBug(3,2) above should behave like this:

  • c.act(): Bug act method.
  • c.act(): Bug act method.
  • c.act(): Bug act method.
  • c.act(): just move()
  • c.act(): just move()
  • c.act(): Bug act method.
  • c.act(): Bug act method.
  • c.act(): Bug act method.
  • c.act(): just move()
  • c.act(): just move()
  • c.act(): no response