Assignment

Topics

• If statements (if-else, if-else if-else, nested-if statements)

• Expressions

• String methods: indexOf (String), substring(int, int), compareTo(String)

Use the following Guidelines:

• Give identifiers semantic meaning and make them easy to read (examples numStudents, grossPay, etc).

• Keep identifiers to a reasonably short length.

• User upper ease for consul. Use fide ease (first letter is upper case) for classes. Use lower case with uppercase word separators for all other identifiers (variables. methods. objects).

• Use tabs or spaces to indent code within blocks (code surrounded by braces). This includes classes, methods, and code associated with ifs, switches and loops. Be consistent with the number of spaces or tabs that you use to indent.

• Use white space to make your program more readable.

Important Note:

All submitted assignments must begin with the descriptive comment block. To avoid losing trivial point, make sure this comment header is included in every assignment you submit, and that it is updated accordingly from assignment to assignment.

Your programming assignments require individual work and effort to be of any benefit. Every student must work independently on his or her assignments. This means that every student nest ensure that neither a soft copy nor a hard copy of their work gets into the hands of another student. Sharing your assignments with others in any way is NOT permitted.

Part 1: Writing Exercise:

The following are questions mostly from chapter 3 in your book.

a. Suppose x and y are variables of type double. Write a code fragment that sets y to x if x is positive and to 0 otherwise

b. Write an expression to check whether an integer variable named nun is even.

c. Write a statement that will assign a true value to a Boolean type if the variable named str is equal to "A SU", and false otherwise.

d. Consider the following code snippet.

If (! (! (a == 1) && (b == 0)))

System.out.println("true");

Describe what the values for a and b must be for the program to output "TRUE". In other words, list up all cases when the expression will be true such as (a, b) = (0, 0) 1, 0), etc. Assume that a and b can be either 0 or 1.

e. Consider the Mowing code, explain the difference. Show the value of s for the Mowing set of input test cases:

1. if x=1 & y =0

2 if x=-1 & y =0

3 if x=1 & y =-1

4. if x=1 & y =1

s = 0;

if (x >0) {s++;}

else if (y>0) {s++;}

Part 2: Programming

Write a java program called Assignment.java. Your task is to implement a simple calculator. Your program will print a menu; ask the user for two numbers and computes the result based on user option. This program will follow a very simple process.

Get input → Calculate → Display result

Task: Prompt the user to enter two numbers as operands (type double), then print a menu to let user know what options are available (use \n and \t for formatting). Read the user's selection to determine which operation the user has chosen. Use a switch statement with user input as the switch expression. Your switch has to provide two cases for each operation; for example "ADD" or "*". For example, if the user enters ADD (in any combination of uppercase or lowercase letters) or a plus sign (+), your program will execute the addition and output the result.

Use only the Java statements that have been covered in class to date. DO NOT use any other statements (loop array, break, etc.) or topic. If in doubt, ask your TA or instructor.

• The Assigamenet.java should have the following, in order:

• In comments, the assignment Header described in "Important Note".

• In comments, the answers to questions a-e presented In Port 1.

• The working lays code requested in Part 2.

• The Assignmenet.java file must compile and run as you submit it. You can confirm this by viewing your submission results.