CS173: Intro to Computer Science - Tell a Story with Conditionals (100 Points)

Assignment Goals

The goals of this assignment are:

1. To use conditionals to solve problems enabling custom control flow
2. To read user input from the console

Background Reading and References

Please refer to the following readings and examples offering templates to help get you started:

• Conditionals Activity

The Assignment

In this lab, you will use conditionals to alter your program’s control flow (that is, flow from one line of code to the next). We can use if statements to conditionally execute code, or to make a choice between two or more pieces of code to run. Then, you will use conditionals to create an narrate an interactive story.

Part 1: Implementing a Venn Diagram

Begin by drawing a three-way Venn Diagram of your choice. For example, this Venn Diagram sorts characters by whether they have been in the Marvel Cinematic Universe, won an academy award, and/or performed on Broadway. Whatever you choose, make sure at least one item fits into each category. You can draw your diagram using software like Microsoft Paint or PowerPoint, or on paper and taking a picture. Either way, be sure to submit it with your project!

Next, write a program that implements your Venn Diagram. That is, write a series of if/else if/else statements, or nested if statements, that sets boolean variables representing each of the three main quadrants of your Venn Diagram, and prints to the screen where that person/place/thing fits into your Venn Diagram based on those if statements. You can number the qudrants from 1 to 7, if you like, and print which quadrant results from the three boolean variables.

Hint: Nested versus Cascading if Staetments

If your if statements look like this:

// this is a nested if statement
if(something) {
    if(somethingElse) {
        // do something
    }
}

you could also write it like this:

// this is a cascading if statement
if(something && somethingElse) {
   // do something
}

Hint: else/if Statements

You can create your own “waterfall” of else/if statements using a shortcut notatation for the nested and cascading if statements above. For example:

double temperature = 50;

if(temperature > 90) {
  System.out.println("It's going to be hot out!");
} else if(temperature > 50) {
  System.out.println("It's going to be comfortable.");
} else if(temperature > 32) {
  System.out.println("It's above freezing!");
} else {
  System.out.println("It's freezing out!");
}

Hint: Automatically Formatting Your Code

Using NetBeans, you can automatically format your code by going to the Source menu and choosing Format. This will automatically align your curly braces and indent your code appropriately. Please feel free to use this early and often as you write your code!

Part 2: Using Conditionals to Tell a Story

Using if and if/else statements, write a program to tell an interactive story. You can ask the user questions and have them enter their answer. Depending on what they say, you can print one message or another in response to them. You can be creative here! Whatever you decide, your story should have at least three opportunities to enter a response (this could be a choice to walk from one room to another in your story, or to pick up an object, or to talk with someone, or take some action, etc). At least once, your story should make a decision based on what the user just entered, and something else that has happened along the way. In other words, you should have at least one compound if statement (using an && or an ||, a nested if statement, or a cascading if statement in your story.

Hint: Reading User Input

Did you know that you can read values from the console window into variables? You can read in all kinds of data types (numbers, text, and so on), which we’ll explore later. For now, here’s how you can read in a String that the user can type in:

// add this to the top of your program, under the line that starts with the word "package"
// import java.util.Scanner;

// and you can do this in main():
Scanner input = new Scanner(System.in);

System.out.println("What is your name?");
// this next line will pause to allow the user to type in something in the console window
// and whatever they type will go into the name variable when they hit <enter>!
String name = input.nextLine(); 

System.out.println("Your name is: " + name);

Hint: Checking String Equality

To check if two Strings are equal, you can do this:

String str1 = "some string";
String str2 = "some other string";


// if they're equal
if(str1.equals(str2)) {

}

// if they're not equal
if(!str1.equals(str2)) {

}

For example:

// add this to the top of your program, under the line that starts with the word "package"
// import java.util.Scanner;

// and you can do this in main():
Scanner input = new Scanner(System.in);

System.out.println("What is your name?");
// this next line will pause to allow the user to type in something in the console window
// and whatever they type will go into the name variable when they hit <enter>!
String name = input.nextLine();

if(name.equals("Bill")) {
    System.out.println("Hi, Bill!");
}

What to Do: Make an Interesting Story

You can add some depth to your story by setting a variable or two depending on the user’s responses to your questions. You can use those variables in if statements later, which will make it seem as though your story “remembered” the user’s responses!

// add this to the top of your program, under the line that starts with the word "package"
// import java.util.Scanner;

// and you can do all of the following inside your main() function, as usual:
Scanner input = new Scanner(System.in); // this is only needed once!

System.out.println("What is your name?");
// this next line will pause to allow the user to type in something in the console window
// and whatever they type will go into the name variable when they hit <enter>!
String name = input.nextLine();

// Assume isBill is false, and then we can set it to true conditionally (if name is "Bill").
boolean isBill = false; // declare this in main, outside of your if statements
if(name.equals("Bill")) {
    isBill = true; // you can change the value within your if statements
}

// later on...

if(isBill) {
    // do you remember what the \' does in the printed String below?
    System.out.println("Earlier, you said your name is Bill!  It\'s nice to meet you."); 
}

Extra Credit (Up to 10%): Best Story Competition

Creativity is encouraged, but not required for a grade! Let me know in your documentation if you’d like to demo your story to the class - I hope you do! You will receive 5% extra credit for entering your submission, and the class will vote on their favorite story (the winner will receive an additional 5% extra credit).

Finishing Touches and Writeup

Don’t forget to test your program with several different inputs to help verify that things work the way you expect! Think in terms of trying to break your program; if it’s really hard to “trick” your program into getting the wrong answer, you’ve probably done a good job making your code robust.

Also, check the Style Guide to make sure that you’ve written high quality code; make sure your code is “readable,” well indented, uses good variable names, and includes good comments throughout the program.

When you’re done, write a README for your project, and save all your files, before exporting your project to ZIP. In your README, answer any bolded questions presented on this page. In addition, write a few paragraphs describing what you did, how you did it, and how to use your program. If your program requires the user to type something in, describe that here. If you wrote functions to help solve your problem, what are they, and what do they do? Imagine that you are giving your program to another student in the class, and you want to explain to them how to use it. What would you tell them? Imagine also that another student had given you the functions that you wrote for your program: what would you have wished that you knew about how to call those functions?

Exporting your Project for Submission

Here is a video tutorial describing how to write a README for your project, and how to export it. Be sure to save your README file before exporting the project, so that your work is included in the submission!

Submission

In your submission, please include answers to any questions asked on the assignment page in your README file. If you wrote code as part of this assignment, please describe your design, approach, and implementation in your README file as well. Finally, include answers to the following questions:

• Describe what you did, how you did it, what challenges you encountered, and how you solved them.
• Please answer any questions found throughout the narrative of this assignment.
• If collaboration with a buddy was permitted, did you work with a buddy on this assignment? If so, who? If not, do you certify that this submission represents your own original work?
• Please identify any and all portions of your submission that were not originally written by you (for example, code originally written by your buddy, or anything taken or adapted from a non-classroom resource). It is always OK to use your textbook and instructor notes; however, you are certifying that any portions not designated as coming from an outside person or source are your own original work.
• Approximately how many hours it took you to finish this assignment (I will not judge you for this at all...I am simply using it to gauge if the assignments are too easy or hard)?
• Your overall impression of the assignment. Did you love it, hate it, or were you neutral? One word answers are fine, but if you have any suggestions for the future let me know.
• Any other concerns that you have. For instance, if you have a bug that you were unable to solve but you made progress, write that here. The more you articulate the problem the more partial credit you will receive (it is fine to leave this blank).

Assignment Rubric

Description	Pre-Emerging (< 50%)	Beginning (50%)	Progressing (85%)	Proficient (100%)
Algorithm Implementation (60%)	The algorithm fails on the test inputs due to major issues, or the program fails to compile and/or run	The algorithm fails on the test inputs due to one or more minor issues	The algorithm is implemented to solve the problem correctly according to given test inputs, but would fail if executed in a general case due to a minor issue or omission in the algorithm design or implementation	A reasonable algorithm is implemented to solve the problem which correctly solves the problem according to the given test inputs, and would be reasonably expected to solve the problem in the general case
Code Indentation and Spacing (10%)	Code indentation and spacing are generally inappropriate or inconsistent	Code indentation or spacing are generally appropriate but inconsistent in a few isolated instances	Code indentation or spacing are appropriate or consistent, with minor adjustments needed	Code indentation and spacing are appropriate and consistent
Code Quality (10%)	Prior code quality feedback and style guide standards are not reflected in the submitted code to a great extent	Code quality conforms to several standards in the course Style Guide, and progress is demonstrated in improving code quality from prior feedback	Code quality conforms to the standards in the course Style Guide to a great extent, with a few identified areas of improvement	Code quality substantially conforms to the standards in the course Style Guide
Code Documentation (10%)	Code commenting and structure are absent, or code structure departs significantly from best practice	Code commenting and structure is limited in ways that reduce the readability of the program; specifically, javadoc style comments are present for some functions	Code documentation is present that re-states the explicit code definitions	Code is documented at non-trivial points in a manner that enhances the readability of the program; specifically, javadoc style comments are present for all functions
Writeup and Submission (10%)	An incomplete submission is provided, or the README file submitted is blank	The program is submitted, but not according to the directions in one or more ways (for example, because it is lacking a readme writeup or missing answers to written questions)	The program is submitted according to the directions with a minor omission or correction needed, including a readme writeup describing the solution and answering nearly all questions posed in the instructions	The program is submitted according to the directions, including a readme writeup describing the solution and answering all questions posed in the instructions

Please refer to the Style Guide for code quality examples and guidelines.