CS46A Fall 18

5A

Write a class called AnalyzingNumbers which will ask the user for two doubles and print out comments based on their values. (no starter file. You will write all the code)

Use this exact prompt to get input:

System.out.print("Enter two doubles (like this: 41.7 -22.5): ");


The user will enter both numbers on the same line at the same time. This is possible because the first call to nextDouble will skip any leading white spaces and then read up to the next white space (the space), leaving that space in the input stream. The second call to nextDouble will ignore leading white spaces and then read up to the next white space (the newline) leaving the newline in the input stream. This is a handy way to request multiple inputs.

Here are the conditions and the comments to print.

Copy and paste the prompt and the replies. That way you will have exactly what Codecheck expects. Print the comments in the order given above

Use the appropriate if structures. Do not use unnecessary tests or have do-nothing if or else statements.

Note for advanced students: Do not use System.exit().Codecheck will not be happy.

For the draft, do the first step. And then print System.out.println("All done"); (Only print All done in the draft)

5A draft:
5A final:

5B

We do not want users of our classes to be able to set invalid values for instance variables. Now that you know how to use if statements, you are going to add error checking to a few classes from earlier homeworks. You can copy correct solutions from my solutions if you need to.

You should not print error messages from constructors or methods of an object. In the real world, you might throw an exception when the parameter is invalid, but we have not covered exceptions yet. We will just be sure the data in our objects are valid. Follow the directions below to add error checking to each class.

Use proper if structure. Do not do unnecessary tests . Do not have empty if or else blocks

SnowGlobe (hw4)

• Modify the code
  • If you did not do so in hw4, modify both constructors to call setRadius. This is a best practice and means you only have to do the error checking in one place in the code.
  • Add a constant DEFAULT_RADIUS to the class. Its value is 10. Use it in your code instead of the literal 10.
  • Add a constant to the class called MAX_RADIUS. Set its value to 50. Use it in your code instead of the literal 50.
  • If the radius is 0 or less, the radius is set to the default
  • If the radius is greater than the maximum, set it to the maximum.

Person (hw3)

• If the person's name is "John Jacob Jingleheimer Schmidt" change it to "John Smith".
• If the age is negative, set it to 0. Also we assume a person's age can never be more than 2 digits. If the age is greater than 99, set it to 99. Define a constant. You will need to modify both the constructor and the haveBirthday method. I defined a private method setAge and had both the constructor and the haveBirthday method call it. That way the tests were done in only one place. It is private because we do not want the user to be able to set an arbitrary age.

ChocolateKissesStash (hw 3)

• The maximum capacity can not be negative. If the value is negative, set it to 0.
• In the eat method,
  • You can not eat a negative amount so only update current amount if the amount to eat is greater than 0
  • The current amount should never be 0. You can not eat more than the current amount, so it the person tries to eat more than that, set the current amount to 0
• In buyMore method
  • You can not buy a negative amount, so only update the current amount in the stash if the amount to buy is greater than 0
  • The current amount can not exceed the capacity of the stash. If the amount to buy would make current amount greater than the capacity, set the current amount to the capacity.

For the draft, just make the changes to SnowGlobe

For the final, you will submit two classes: Person.java and ChocolateKissesStash.java. Note that there are 2 testers this time.

5B draft:
5B final:

5C

Complete the class RestaurantHelper to help restaurant customers with the bill.

It has the following constructor:

public RestaurantHelper(double mealCost, int serviceQuality)where serviceQuality is an int 0 to 3 which represents the quality of service. 0 is poor service, 1 is fair, 2 is good, and 3 is excellent service. Define and use constants for the quality of service like this:

• public static final int EXCELLENT_SERVICE = 3;
• public static final int GOOD_SERVICE = 2;
• and so forth

The constructor will initialize the instance variables.

• If the mealCost is negative, set cost to 0.
• If the serviceQuality is greater than EXCELLENT_SERVICE (3), set service quality to EXCELLENT_SERVICE. If it is negative, set it to POOR_SERVICE. otherwise set it to the parameter.

Provide methods:

• public double tip() Gets the amount of the tip as a percentage of the costOfMeal according to the quality of service level. Just have one return statement
• public double tax()Gets the amount of the tax The tax rate is 9%
  Define and use a constant.
  
• public double totalCost() Gets the total cost including tip and tax. Do not calculate tip or tax in this method. Call the methods already written
• public int qualityOfService() Gets the quality of service (provided)
• public double costOfMeal() Gets the base cost of the meal (no tip or tax) (provided)

Below is a table of the tip for different quality of service levels. The tip is a percentage of the bill.

Define and use constants for the percentages like this

• public static final double EXCELLENT_TIP = .25;
• public static final double GOOD_TIP = .20;
• and so forth

Provide Javadoc.

5C draft:
5C final: