CSS142 HW1: Branching

Summary

This is a brief warm-up exercise regarding branching.

Work Item

Given the following variable declarations and main method skeleton driver below in "Main Method Skeleton Driver", code up "if" statements that correspond with each of the "Questions" below. (A driver is a program whose purpose is to run other code, in this case, the "if" statements.)

Compile and execute your code to prove it’s correct. Use a Scanner for reading in from the keyboard.

For assingment submission, you will add all your code to this GitHub repository. Your instructors will grade the code files in this repository; there is no need to submit anything via Canvas or email.

There is a Java file in this repository called HW_WarmUp.java. This is the file which should contain all of your coded solutions; do not rename this file or create other class files for this assignment.

There is no flow chart for this assignment.

Questions

1. Prompt the user with: "Enter the number". Determine if it is negative and if so, print: "The number is negative." Use a Scanner to collect the input, and report to the console if the variable called number is negative using System.out.println().
2. Prompt the user with: "Enter a second number". Determine if the number is zero and if so, print: "The number is zero." Use a Scanner to get the input, and report if the number is zero next. You can reuse the variables "number" and "keyboard" here.
3. Continue to use Scanner for input. Prompt the user with: "Enter a third number, a double, for the class average." Determine if the class average is a passing grade, and if so, print: "A passing grade", and print to the console otherwise if not. Not passing is if the class average was below a
5. Prompt the user with: "Is the answer the user reported true? Enter a Boolean value." Store the value in the variable called "answer". Let the user know if the value in the variable “answer” is true by printing an appropriate message to the console.
6. Starting with the "if" statement you built in the previous problem, add an "else" clause to it so that if the answer was false, your program will output "The value was false" instead.
7. Ask the user for a number and then determine if the number is even or odd. Print out “the number is even” if the “number” variable holds an even value, else { print out “the number is odd” }
8. Ask the user for a float value that will represent a grade and determine if the grade is in the “A” range. Print to the console “The grade is above an X” (where X is the minimum value for an "A" grade) if the grade is an “A”. (You can decide for yourself what percentage is an "A" grade.)
9. Add to the previous "if" statement so that it becomes an "if/else" or multi-way if/else structure that will now also test to see if the grade is a “B”. Output to the console if the grade is in that range. (While you don't necessarily have to use the logical "and" operator to solve this problem, note that in Java the "and" operator is represented by “&” or “&&”.) You can decide for yourself what percentage is a "B" grade.
10. Ask the user for a temperature, stored in a double. Is the temperature higher than 78 degrees or less than (or equal to) 78 degrees? Describe the current temperature as “higher than 78 degrees” or “less than or equal to 78 degrees”.
11. For the temperature, write an "if/else" statement that asks if the temperature is (positive & odd) OR (zero & even)? (Notice the use of parenthesis here to define operator precedence. Look up order of operations (PEMDAS), "logical AND," and “logical OR” if this is unfamiliar in your text). If it is, output “yes; positive and odd or zero and even” and if it’s not, say “no; not positive and odd or zero and even” on the console.
12. Prompt the user for a letter grade and store this in a char. Then, write a multi-way "if" statement that ends in a catch-all if a non-existent letter grade (i.e., not A, B, C, D, F) is entered. The multi-way "if" asks: Is the grade an “A”? Else is the grade a “B”? Else is the grade a “C”? Else is the grade a “D”? Else is the grade an “F”? For each case, print an appropriate message to screen as to what letter grade was entered (or if a non-existent grade was entered). Notice the use of the word else in the sentence above, which provides for a more precise meaning. In spoken English we might use the word “or” instead, but of course, English is terribly ambiguous and Java needs to be discrete, deterministic, and precise.
13. Write a function called “max” that takes two integers as input and returns the larger of the two. That is, complete the function “public static int max(int a, int b) {“ so that it returns the larger of a or b using an “if” statement.
14. Ask the user for two integers using a Scanner and report the largest and smallest values using the max function you just built. Consider the following output:

//sample output for problem 13
Enter two integers: 2 14
Largest is 14
Smallest is 2

Grading

Each item is given zero, half or 1 point. For this assignment, points are awarded strictly based on whether your program is correctly written to produce the correct results. You will not be graded on style, though you should always practice good programming style.

Additional Hints

Always compile and run/test your code after each incremental change. Never write a whole program first and then compile and test later.

Initial Setup

Accept the assignment with this link.

Go to your assignment repository.

Clone the starter code onto your desktop with GitBash. You can get GitBash here: https://gitforwindows.org/

Change directory to your desktop and clone your repository by executing each of these commands separately.

cd Desktop/
git clone <HTTPS URL>

You can find the HTTPS URL here:

You may be prompted for your login information so enter that in.

Now, open up your preferred IDE, and open the cloned GitHub folder as a new project. Once you have opened the project in your IDE, you can edit the HW_WarmUp.java file and implement the solutions required for this assignment.

Submitting your assignment

When you feel like you have completed a significant task for your assignment, you should commit those changes and push them to Github.

Execute the following commands on GitBash:

cd path/to/cloned/project           # Replace this path with the path to your GitHub repository
git add HW_WarmUp.java
git commit -m "Implement things"    # Write a meaningful commit message so you can understand what changes you made
git push

You can push commits to your project anytime you like; it's a good practice to commit early and often, and push your commits to your GitHub repository to get feedback from the automated testing in the repository.

Credits

About this Document By Rob Nash, et al., January 2016, with minor edits by Johnny Lin, last December 2017.

GitHub Submissions By David Liu and Lizzy Presland, Spring 2020