Java Arrays / FIle input / File output

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Java Programming Assignment For Arrays, File Input, And File Output

For use in Eclipse.

A teacher has 10 students who have taken the course.  The teacher uses the following grading scale to assign a letter grade to a students, based on the average of his or her four test scores:

Avg Test score  Letter grade

90-100 A

1. B

1. C

1. D

1. E

Assume that teacher has stored the following information in different files:

Lname.txt stores last names of students (string)

Fname.txt stores first names of students (string)

Exam1.txt stores exam 1 score (double)

Exam 2.txt stores exam 2 score (double)

Exam 3.txt stores exam 3 score (double)

Exam 4.txt stores exam 4 score (double)

In each case, the corresponding entries match in each file, that means, first element of each file corresponds to the first student, second for second student and so on.

Write a program that reads data from each file and stores in a separate array, except that String array named fullName contains the string representing full name of the student as follows:  "John Kennedy"  where "Kennedy" is picked up from Lname.txt, and "John" is selected from corresponding position in Fname.txt file. Create double arrays named Ex1, Ex2, Ex3, and Ex4 to score corresponding scores read from the files. 

Write the following methods:getAvg (to return average of all elements of an array passed as a parameter), 

getMax  (to find the largest element of an array passed as a parameter),

getMin (to find the smallest element of an array passed as a parameter).

computeAverage method which accepts 4 double parameters (for each exam score) and returns a double value representing the average. computeGrade method which accepts a double value (average) and returns a letter grade (char type). 

Using computeAverage method, compute and store the average for each student in a double array titled exAvg.

Using computeGrade method, compute and store the letter grade for each student in a char array titled grade. 

Output

After calculating the average test score, and the grade for each student, obtain the following output (on console using printf statement): Tabulated output for students with proper heading (sample output) – first line is the header --

Full Name of Student  Ex1 Ex2 Ex3 Ex4 Avg Grade

John Kennedy 78.0 73.0 83.0 78.0  78.0 C 

(for all students) etc.

Print the statistics for each exam (by using appropriate method calls)

Exam Number  Max. Score  Min Score  Average Score

Exam 1 99.2 43.9 72.9 

Similarly, print these values for Exam 2, Exam 3, Exam 4, and AvgTestScore. 

Creation of Data sets

For each of the data sets, first 5 entries are to be entered as shown—Add another 5 entries of your choice data

Lname.txt Fname.txt Exam1.txt Exam2.txt Exam3.txt Exam4.txt

Gates  Lisa 87 76 92 88

Kramer Bill 65 72 83 64

Winfry Susan 91 90 87 99

Einstein Matt 57 75 79 56

Jobs Cindy 74 84 94 97

(add 5 more entries in each file of your choice)

Make the files yourself using a text edit program on your computer and put them into your project computer in eclipse

Here is the code for the assignment. You'll have to indent it yourself

import java.io.File;

import java.io.IOException;

import java.io.PrintStream;

import java.util.ArrayList;

import java.util.Scanner;

/**

 * 

 * @param args

 */

public class EnterYourClassNameHere{

public static double[] readScoreFile(String fileName) throws IOException {

// Read the file name and store it

double value;

ArrayList<Double> result = new ArrayList<Double>();

Scanner sc = new Scanner(new File(fileName));

while (sc.hasNextDouble()) {

value = sc.nextDouble();

result.add(value);

}

sc.close();

double[] arr = new double[result.size()];

for (int i = 0; i < arr.length; i++) {

arr[i] = result.get(i);

}

return arr;

}

public static ArrayList<String> readFile(String fileName)

throws IOException {

// Read Name and Store names

ArrayList<String> result = new ArrayList<String>();

Scanner sc = new Scanner(new File(fileName));

while (sc.hasNextLine()) {

String line = sc.nextLine().trim();

if (!line.equals("")) {

result.add(line);

}

}

sc.close();

return result;

}

// Read Array full name

public static String[] readFullName(String fnameFile, String lnameFile)

throws Exception {

ArrayList<String> fname = readFile(fnameFile);

ArrayList<String> lname = readFile(lnameFile);

int size = fname.size();

if (size > lname.size()) {

size = lname.size();

}

String[] fullName = new String[size];

for (int i = 0; i < size; i++) {

fullName[i] = fname.get(i) + " " + lname.get(i);

}

return fullName;

}

// return Average

public static double getAvg(double[] arr) {

double sum = 0;

for (int i = 0; i < arr.length; i++) {

sum += arr[i];

}

return sum / arr.length;

}

// Return max

public static double getMax(double[] arr) {

double max = arr[0];

for (int i = 1; i < arr.length; i++) {

if (max < arr[i]) {

max = arr[i];

}

}

return max;

}

// return Min

public static double getMin(double[] arr) {

double min = arr[0];

for (int i = 1; i < arr.length; i++) {

if (min > arr[i]) {

min = arr[i];

}

}

return min;

}

// Compute Average

public static double computeAverage(double score1, double score2,

double score3, double score4) {

return (score1 + score2 + score3 + score4) / 4;

}

// Score

public static char computeGrade(double score) {

if (score >= 90) {

return 'A';

} 

else if (score > 80) {

return 'B';

} 

else if (score > 70) {

return 'C';

} 

else if (score > 60) {

return 'D';

} 

else {

return 'E';

}

}

// For output

public static void main(String[] args) throws Exception {

String[] fullName = readFullName("Fname.txt", "Lname.txt");

double[] Ex1 = readScoreFile("Exam1.txt");

double[] Ex2 = readScoreFile("Exam2.txt");

double[] Ex3 = readScoreFile("Exam3.txt");

double[] Ex4 = readScoreFile("Exam4.txt");

char[] grade = new char[fullName.length];

double[] exAvg = new double[fullName.length];

for (int i = 0; i < grade.length; i++) {

exAvg[i] = computeAverage(Ex1[i], Ex2[i], Ex3[i], Ex4[i]);

grade[i] = computeGrade(exAvg[i]);

}

PrintStream ps = new PrintStream(new File("PA9OutFile.txt"));

System.out

.println("Full Name of Student    Ex1 Ex2 Ex3 Ex4 Avg Grade");

ps.println("Full Name of Student Ex1 Ex2 Ex3 Ex4 Avg Grade");

System.out.println("-----------------------------------------------------------");

ps.println("-----------------------------------------------------------");

for (int i = 0; i < grade.length; i++) {

System.out.println(String.format("%-23s %5.1f %5.1f %5.1f %5.1f %5.1f %c", fullName[i],

Ex1[i], Ex2[i], Ex3[i], Ex4[i], exAvg[i], grade[i]));

ps.println(String.format("%-23s %5.1f %5.1f %5.1f %5.1f %5.1f %c",

fullName[i], Ex1[i], Ex2[i], Ex3[i], Ex4[i], exAvg[i],grade[i]));

}

System.out.println();

ps.println();

System.out

.println("Exam Number Max Score Min Score Average Score");

ps.println("Exam Number Max Score Min Score Average Score");

System.out

.println("-----------------------------------------------------");

ps.println("----------------------------------------------------");

double min = getMin(Ex1);

double max = getMax(Ex1);

double avg = getAvg(Ex1);

System.out.println(String.format("Exam1 %3.1f %3.1f %3.1f", max, min,avg));

ps.println(String.format("Exam1 %3.1f %3.1f %3.1f", max, min,avg));

min = getMin(Ex2);

max = getMax(Ex2);

avg = getAvg(Ex2);

System.out.println(String.format("Exam2 %3.1f %3.1f %3.1f", max, min,avg));

ps.println(String.format("Exam2 %3.1f %3.1f %3.1f", max, min,avg));

min = getMin(Ex3);

max = getMax(Ex3);

avg = getAvg(Ex3);

System.out.println(String.format("Exam3 %3.1f %3.1f %3.1f", max, min,avg));

ps.println(String.format("Exam3 %3.1f %3.1f %3.1f", max, min,avg));

min = getMin(Ex4);

max = getMax(Ex4);

avg = getAvg(Ex4);

System.out.println(String.format("Exam4 %3.1f %3.1f %3.1f", max, min,avg));

ps.println(String.format("Exam4 %3.1f %3.1f %3.1f", max, min,avg));

ps.close();

}

}