Description
Overview: You will write two programs this week. The first will compute the value generated by a
specified expression and the second will read data for a football ticket and then interpret and print the
formatted ticket information.
• FormulaEval.java
Requirements: Calculate the following expression for a value x of type double which is read in
from the keyboard, and save the result of the expression in a variable of the type double. You
must use the sqrt(), abs() and pow() methods of the Math class to perform the calculation.
You may use a single assignment statement with a single expression, or you may break the
expression into appropriate multiple assignment statements. The latter may easier to debug if you
are not getting the correct result.
����� + %|�. ��� − �� + �|
(�. ��� + �. �� + �. �)
Next, determine the number of characters (mostly digits) to the left and to the right of the decimal
point in the unformatted result. [Hint: You should consider converting the type double result into
a String using the static method Double.toString(result) and storing it into a String
variable. Then, on this String variable use the indexOf(“.”) method from the String class to
find the position of the period (i.e., decimal point) and the length() method to find the length
of the String. Knowing the location of the decimal point and the length, you should be able to
determine the number of digits on each side of the decimal point.]
Finally, the result should be printed using the class java.text.DecimalFormat so that to the right of
the decimal there are at most five digits and to the left of the decimal each group of three digits is
separated by a comma in the traditional way. Also, there should also be at least one digit on each
side of the decimal (e.g., 0 should be printed as 0.0). Hint: Use the pattern “#,##0.0####” in your
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DecimalFormat constructor. However, make sure you know what this pattern means and how to
modify and use it in the future.
Design: Several examples of input/output for the FormulaEval program are shown below.
Line number Program output
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Enter a value for x: 0
Result: 0.2631578947368421
# of characters to left of decimal point: 1
# of characters to right of decimal point: 16
Formatted Result: 0.26316
Line number Program output
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Enter a value for x: 15.3
Result: 40.76517723751596
# of characters to left of decimal point: 2
# of characters to right of decimal point: 14
Formatted Result: 40.76518
Line number Program output
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Enter a value for x: -15.3
Result: -40.03373803500063
# of characters to left of decimal point: 3
# of characters to right of decimal point: 14
Formatted Result: -40.03374
Line number Program output
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Enter a value for x: 9876543210987654321
Result: 3.878955567931786E9
# of characters to left of decimal point: 1
# of characters to right of decimal point: 17
Formatted Result: 3,878,955,567.93179
When the characters to the right of the decimal in the unformatted result end with E followed
by one or more digits (e.g., E9 indicates an exponent of 9), the ‘E’ should be included in the
count of the characters to the right of the decimal point.
Code: In order to receive full credit for this assignment, you must use the appropriate Java API
classes and method to do the calculation and formatting. It is recommended as a practice that you
do not modify the input value once it is stored.
Test: You will be responsible for testing your program, and it is important to not rely only on the
examples above. Assume that the amount entered can be any positive or negative floating-point
number.
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• FootballTicket.java
Requirements: The purpose of this program is to accept coded football ticket information as
input that includes the ticket price, category, time, date, seat, row, section, followed by the
description of the game. Note that the five digits for price have an implied decimal point. The
program should then print the ticket information including the actual cost, which is the price with
discount applied (none for regular tickets (anything but s or f), 67% for student tickets
(s), and 20% for faculty/staff tickets (f). The last line of the ticket should contain a random
“prize number” between 1 and 9999999 inclusive that should always be printed as seven digits
(e.g., 1 should be printed as 0000001). The coded input is formatted as follows:
r12500143009152018213105Auburn vs LSU
date section game description
row (goes through last character in the code)
seat
time
price [12500 has an implied decimal point for 125.00]
category [s, f, or anything else is a regular ticket with no discount]
Whitespace before or after the coded information should be disregarded (e.g., if the user enters
spaces or tabs before or after the coded information, these should be disregarded). Your program
will need to print the game description, the date and time, the section, row, and seat number, the
ticket price, the ticket category, the actual cost, and a random prize number in the range 1 to
9999999. If the user enters a code that does not have at least 25 characters, then an error message
should be printed. [The 25th character of the code is part of the game description.]
Design: Several examples of input/output for the program are shown below.
Line # Program output
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Enter your ticket code: 123456789
Invalid Ticket Code.
Ticket code must have at least 25 characters.
Note that the ticket code below results in the indicated output except for the prize number which
is random. When more than one item is shown on the same line (e.g., game, date, and time on
line 3), there are three spaces between them (do not use the tab escape sequence \t).
Line # Program output
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Enter your ticket code: r12500143009152018213105Auburn vs LSU
Game: Auburn vs LSU Date: 09/15/2018 Time: 14:30
Section: 5 Row: 31 Seat: 21
Price: $125.00 Category: r Cost: $125.00
Prize Number: 3354928
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Line # Program output
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Enter your ticket code: s12500143009152018213105Auburn vs LSU
Game: Auburn vs LSU Date: 09/15/2018 Time: 14:30
Section: 5 Row: 31 Seat: 21
Price: $125.00 Category: s Cost: $41.25
Prize Number: 4247895
Note that the ticket code below has five leading spaces (be sure you are trimming the input code).
Line # Program output
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Enter your ticket code: f12500143009152018213105Auburn vs LSU
Game: Auburn vs LSU Date: 09/15/2018 Time: 14:30
Section: 5 Row: 31 Seat: 21
Price: $125.00 Category: f Cost: $100.00
Prize Number: 0241193
Code: In order to receive full credit for this assignment, you must use the appropriate Java API
classes and methods to trim the input string, to do the extraction of the category character,
extraction of the substrings, conversion of substrings of digits to numeric values as appropriate,
and formatting. These include the String methods trim, charAt, and substring, as well as wrapper
class methods such as Integer.parseInt and Double.parseDouble which can be used to convert a
String of digits into a numeric value. The dollar amounts should be formatted so that both small
and large amounts are displayed properly, and the prize number should be formatted so that seven
digits are displayed including leading zeroes, if needed, as shown in the examples above. It is
recommended as a practice that you not modify input values once they are stored. While not a
requirement, you should consider making the student discount and faculty/staff discount
constants. For example, the following statements could be placed above the main method.
static final double STUDENT_DISCOUNT = 0.67;
static final double FACULTY_STAFF_DISCOUNT = 0.20;
Test: You are responsible for testing your program, and it is important to not rely only on the
examples above. Remember, when entering standard input in the Run I/O window, you can use
the up-arrow on the keyboard to get the previous values you have entered. This will avoid having
to retype the ticket info data each time you run your program.
Grading
Web-CAT Submission: You must submit both “completed” programs to Web-CAT at the same time.
Prior to submitting, be sure that your programs are working correctly and that they have passed
Checkstyle. If you do not submit both programs at once, Web-CAT will not be able to compile and
run its test files with your programs which means the submission will receive zero points for
correctness. I recommend that you create a jGRASP project and add the two files. Then you will be able
to submit the project to Web-CAT from jGRASP. Activity 1 (pages 5 and 6) describes how to create a
jGRASP project containing both of your files.
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Hints
FootballTicket class
1. The ticket code should be read in all at once and stored in a variable of type String, after
which the individual values should be extracted using the substring method. The String value
for price should be converted to type double (using Double.parseDouble) so that it can be
used to calculate cost. When printing the values for price and cost, they should be formatted
properly by creating an appropriate DecimalFormat object and calling its format method.
Since all items other than the price will not be used in arithmetic expressions, they can be left
as String values (or char value in the case of category).
2. Since char values are primitive types, == and != can be used to compare two values for
equality and inequality respectively. Thus, if the category is extracted from the input using
the String method charAt() which returns a char, then == and != can be used to compare char
values.
Otherwise, if category is a String, you should not use == and != to compare two String
values. String values should be compared for equality using the String equals method which
has a boolean return type. For example, if s1 and s2 are String objects, to check to see if their
respective character strings are equal you should use
s1.equals(s2)
rather than
s1 == s2
which is only true if s1 and s2 are aliases for the same String object.
The time and date should have leading zeros as appropriate. Therefore, these can be printed as String
values by concatenating their components with “:” and “/” as needed.
