COSC 236
Lab 10
The goal of this lab is to get used with basic Java notions introduced so far and Java methods (discussed in Lecture #9). Take a look at the
examples and the sample programs in the lecture notes and try to apply the same
concepts and style when writing your own programs. You will write 2 programs,
given below.
1. Write a Java program that
consists of repeated calls to 2 methods to compute the sum and product of all
integers between two bounds. For example if the lower bound is 3 and the upper
bound is 7, the first method will return the sum 25 (3 + 4 + 5 + 6 + 7) and the
second method will return the product 2520 (3 * 4 * 5 * 6 * 7). The program
will include a loop (count controlled or sentinel controlled, your choice);
inside the loop call the methods for various values of the lower bound and
upper bound (user input - make sure you do input validation and check if the
lower bound is less than the upper bound), and print the results.
The following specifications describe a method that computes
the sum of all integers between 2 bounds:
Input
parameters: int lower, int upper (where lower is
the lower bound and upper is the upper bound)
Return:
the sum of all numbers between lower and upper
The following specifications describe a method that computes the product of all integers between 2 bounds:
Input
parameters: int lower, int upper (where lower is
the lower bound and upper is the upper bound)
Return:
the product of all numbers between lower and upper
2. Write a Java program that
uses a value-returning method to identify the prime numbers between 2 bounds
(input from the user). The method should identify if a number is prime or not.
Call it in a loop for all numbers between the 2 bounds and display only prime
numbers. Check for errors in input.
Note: A number is prime if it is larger than
1 and it is divisible only by 1 and itself (Note: 1 is NOT a prime number)
Example: 15 is NOT prime because 15 is
divisible by 1, 3, 5, and 15; 19 is prime because 19 is divisible only by 1 and
19.
Sample run:
How many times to test
for prime numbers? -3
Error! Should be
positive. Reenter: 3
Enter lower
bound/upper bound: 5 3
Error! Lower bound
should be larger. Reenter: 3 15
Prime numbers between
3 and 15 are: 3 5 7 11 13
Enter lower
bound/upper bound: 2 25
Prime numbers between
2 and 25 are: 2 3 5 7 11 13 17 19 23
Enter lower
bound/upper bound: 1 55
Prime numbers between
1 and 55 are: 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53
Notes:
A. The lab will NOT be graded, do NOT hand anything in to the
instructor.
B. The lab should be completed by the start of the next scheduled lab
class. Save the .java files on your disk and e-mail them
(attachments) to Vishal Patel at vpatel12@students.towson.edu
Very important: Make sure that you have COSC 236.section, your name,
and Lab#10 in the Subject box of your e-mail.
C. In case you have any problems, contact the TA or the instructor for
assistance.