I'm trying to write a program to read a file called scores.txt where it prints out the ID of the student with the highest average across their courses along with their student ID.
This is what scores.txt looks like:
34 c081 c082 c083 c084
S2023 99 75 85 62
S2025 -1 92 67 52
S1909 100 83 45 -1
So basically, the 34 a the beginning is a 3 for the number of students and a 4 for the number of courses (yes, I know this is silly, but the file was provided for my task). The c numbers such as c081 are course codes at the school, and the s numbers such as s2023 are student numbers. The figures in the middle represent their scores, the -1 also means they weren't enrolled in the unit.
Anyway, so far I've written a MySchool class and a Student class, which I'll paste below:
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Scanner;
public class MySchool {
public static void main(String[] args) {
int numberOfStudents;
ArrayList<Student> allStudents = new ArrayList<Student>() ;
// grab first line only, and check if first target is integer, or string
try {
File scoresFile = new File("Scores.txt");
Scanner scoresFileReader = new Scanner(scoresFile);
String headerRow = scoresFileReader.nextLine();
numberOfStudents = headerRow.charAt(0);
while(scoresFileReader.hasNextLine()) {
for (int studentI = 0; studentI < numberOfStudents; studentI++) {
String studentText = scoresFileReader.nextLine();
System.out.println(studentText);
Student student = new Student(studentText);
allStudents.add(student);
}}
scoresFileReader.close();
} catch (FileNotFoundException e) {
System.out.println("An error occurred");
e.printStackTrace();
}
float highestAverage = 0;
String highestScoringStudentNumber = null;
for (Student student : allStudents) {
if (student.getAverageScore() > highestAverage) {
highestAverage = student.getAverageScore();
highestScoringStudentNumber = student.getStudentNumber();
}
}
System.out.println("Highest scoring student: " + highestScoringStudentNumber);
}
}
import java.util.ArrayList;
public class Student {
private String studentNumber;
private ArrayList<Integer> scores = new ArrayList<Integer>();
public Student(String studentText) {
String[] parts = studentText.split(studentText, ' ');
this.studentNumber = parts[0];
for (int i = 1; i < parts.length - 1; i++) {
scores.add(Integer.parseInt(parts[i + 1]));
}
}
public String getStudentNumber() {
return this.studentNumber;
}
public float getAverageScore() {
int sum = 0;
for (int i = 0; i <this.scores.size(); i++) {
sum += this.scores.get(i);
}
return sum / this.scores.size();
}
}
Basically I want to be able to have an object for students where they have their student number and their scores. This is so that I can give them an average.
However, it seems that I've done something wrong in reading the file in (Haven't ever done this before), because the String studentText = scoresFileReader.nextLine(); line throws me an error that states : Exception in thread "main" java.util.NoSuchElementException: No line found
at java.base/java.util.Scanner.nextLine(Scanner.java:1651)
at MySchool.main(MySchool.java:22)
If it's any help, the three student codes and their scores print out the way they should before I get this error.
Can anyone help me to get this up and running? I'm not sure how to resolve it
EDIT:
I've actually noticed the issue to be that somehow numberOfStudents is being set to 51 when there's no 51 in the data. Even if I run the code below, it prints the first value of headerRow confirming that it is 3, which is correct. The when I use the same code to assign it to numberOfStudents suddenly it's become 51 when it prints again?
import java.io.File; // Import the File class
import java.io.FileNotFoundException; // Import this class to handle errors
import java.util.ArrayList;
import java.util.Scanner; // Import the Scanner class to read text files
public class MySchool {
public static void main(String[] args) {
int numberOfStudents;
ArrayList<Student> allStudents = new ArrayList<Student>() ;
// grab first line only, and check if first target is integer, or string
try {
File scoresFile = new File("Scores.txt");
Scanner scoresFileReader = new Scanner(scoresFile);
String headerRow = scoresFileReader.nextLine();
System.out.println(headerRow.charAt(0));
numberOfStudents = headerRow.charAt(0);
System.out.println(numberOfStudents);
for (int studentI = 0; studentI < numberOfStudents; studentI++) {
String studentText = scoresFileReader.nextLine();
System.out.println(studentText);
Student student = new Student(studentText);
allStudents.add(student);
}
scoresFileReader.close();
} catch (FileNotFoundException e) {
System.out.println("An error occurred");
e.printStackTrace();
}
float highestAverage = 0;
String highestScoringStudentNumber = null;
for (Student student : allStudents) {
if (student.getAverageScore() > highestAverage) {
highestAverage = student.getAverageScore();
highestScoringStudentNumber = student.getStudentNumber();
}
}
System.out.println("Highest scoring student: " + highestScoringStudentNumber);
}
}
