Description
Objectives:
1. Getting started with Eclipse
2. Write a program to perform simple statistical analysis
Getting started with Eclipse:
1. Run Eclipse. It will ask you to choose a workspace. Create a workspace in your universal disk
space (m: drive).
Check: Go to your m: drive and see where the workspace folder was created
2. Create a new Java project. Name the new project lab1.
Check: Go to your workspace (Package Explorer). If you don’t see it then go to menu and
select the following: “Window→Show View→Package Explorer .”
There should now be a folder named, lab1 in the package explorer. That folder contains
several folders and files which you can see by expanding it (click on the “>” icon to expand
it). It has a folder named, src which will contain our java (source) codes. Initially, it doesn’t
have any java files. We will later add our java code to this folder.
Now, write a program to perform simple statistical analysis:
A professor wants to perform some statistical calculations on his students’ exam scores. Ask the
professor about the number of students he has in the class, read the values and store these grades in
an array, and print the statistical analysis of the grades.
1. Create a java class, GradeStatistics in the source (src) folder of the lab1 project. To do this,
right click on the src folder and select “New→Class”. It will open a window (see figure below)
where you need to write the java class name. You can also select the check-box that says “public
static void main(String[] args)”.
Lab Assignment 01, Object-Oriented Programming, CSE 271, Spring 2020
Department of Computer Science and Engineering, Miami University
Warm-up Lab (Review and Getting started with Eclipse)
Page 2 of 3
2. Now, in the src folder you will see a java file names, GradeStatistics.java. Open it and write the
following methods in it following the method descriptions:
a. public static double[] populateGrades() – construct the array of type double,
create Scanner class object to read in the number of students and their grades from the
keyboard, store the grades in the array and then return that array.
b. public static void sortGrades(double grades[]) – it takes the grades array as an
argument and sorts the values in ascending order (from low to high). You can use
Arrays.sort() method to sort the array.
c. public static double getMean(double grades[]) – it takes the grades array as an
argument, calculates the mean of all values and returns the result.
d. public static double getMedian(double grades[]) – it takes the grades array as
an argument, calculates the median of all values and returns the result.
e. public static double[] getMinMax(double grades[]) – it takes the grades array
as an argument, calculates the minimum and maximum of all values and returns the result
in array. The result array has the minimum and maximum values in index 0 and 1,
respectively.
f. public static void printGrades(double grades[]) – it takes the grades array as
an argument, prints the content of the array from the left (index 0) to right. The grades are
printed in the following format (separated by comma and a space).
Format: 87.0, 89.0, 95.0, 97.0
g. public static void main(String args[])– You need to call the methods you defined
above to complete this method. Here is the order you must follow:
1. Call populateGrades() method and store the returned array
reference using a local array reference.
2. Print the grades using the printGrades() method. You need to pass
the array you populated using populateGrades() method.
3. Sort the grades using sortGrades() method. You can update the
local array reference to store sorted array reference. You can
use the sorted array for rest of the tasks.
4. Print the sorted grades using printGrades() method.
5. Compute mean using the getMean() method and print it.
6. Compute median using the getMedian() method and print it.
7. Find minimum and maximum using getMinMax() method and print.
Once you are done, select the menu: “Run→Run” to execute your program. Two sample runs
are given below. Your program’s output must follow the format shown in the sample runs.
Lab Assignment 01, Object-Oriented Programming, CSE 271, Spring 2020
Department of Computer Science and Engineering, Miami University
Warm-up Lab (Review and Getting started with Eclipse)
Page 3 of 3
Sample Runs: (Inputs from the keyboard are shown in green color)
Grading Rubrics:
Task Grade
Create GradeStatistics class 2
Define populateGrades() method and work correctly 16
Define sortGrades() method and works correctly 10
Define getMean() method and works correctly 12
Define getMedian() method and works correctly 12
Define getMinMax() method and works correctly 12
Define printGrades() method and works correctly 12
Define main() – follows the order, correct format and output 22
Total 100
Submission Instructions:
• After you are done with the task, you need to show your work to one of the instructors
present in the lab.
• Now, locate your source code GradeStatistics.java file at your workspace and submit it
on CANVAS.
Run1: ( this is not part of the output)
How many students do you have in the class: 4
Enter grade of Student 1: 10
Enter grade of Student 2: 100
Enter grade of Student 3: 20
Enter grade of Student 4: 30
The grades are: 10.0, 100.0, 20.0, 30.0
The sorted grades are: 10.0, 20.0, 30.0, 100.0
Mean = 40.0
Median = 25.0
Min = 10.0 Max = 100.0
Run2: ( this is not part of the output)
How many students do you have in the class: 5
Enter grade of Student 1: 100
Enter grade of Student 2: 90.5
Enter grade of Student 3: 95.5
Enter grade of Student 4: 10
Enter grade of Student 5: 20.75
The grades are: 100.0, 90.5, 95.5, 10.0, 20.75
The sorted grades are: 10.0, 20.75, 90.5, 95.5, 100.0
Mean = 63.35
Median = 90.5
Min = 10.0 Max = 100.0