Question

JAVA HELP FOR COMP:

Can someone please modify the code to create LowestGPA.java that prints out the name of the student with the lowestgpa.

In the attached zip file, you will find two files HighestGPA.java and students.dat. Students.dat file contains names of students and their gpa. Check if the code runs correctly in BlueJ or any other IDE by running the code. Modify the data to include few more students and their gpa.

import java.util.*; // for the Scanner class

import java.io.*; // for the File class

public class HighestGPA
{
public static void main (String[ ] args) throws FileNotFoundException
{
new HighestGPA().run();
} // method main   

public void run() throws FileNotFoundException
{
final double NEGATIVE_GPA = -1.0;

final String NO_VALID_INPUT =
"Error: the given file has no valid input.";

final String BEST_MESSAGE =
"\n\nThe student with the highest grade point average is ";

Scanner fileScanner = new Scanner (new File ("students.dat"));   

String name,
bestStudent = null;

double gpa,
highestGPA = NEGATIVE_GPA;

while (fileScanner.hasNextLine())
{   
Scanner lineScanner = new Scanner (fileScanner.nextLine());

name = lineScanner.next();
gpa = lineScanner.nextDouble();
if (gpa > highestGPA)
{
highestGPA = gpa;
bestStudent = name;
} // if
} // while
if (highestGPA == NEGATIVE_GPA)
System.out.println (NO_VALID_INPUT);
else
System.out.println (BEST_MESSAGE + bestStudent);
} // method run

} // class HighestGPA

Students.dat file:

Larry 3.3
Curly 3.7
Moe 3.2

Answer 1

import java.util.*; // for the Scanner class

import java.io.*; // for the File class

// Defines class LowestGPA

public class LowestGPA

{

// main method definition

public static void main (String[ ] args) throws FileNotFoundException

{

// Creates an anonymous object of the class LowestGPA and calls the run() method

new LowestGPA().run();

} // End of method main

// Method to find and display the lowest GPA student name

public void run() throws FileNotFoundException

{

// Creates a constant to store maximum double value

final double MAX_GPA = Double.MAX_VALUE;

// Creates a string constant to store error message for file  

final String NO_VALID_INPUT = "Error: the given file has no valid input.";

// Creates a string constant to store message for student

final String BEST_MESSAGE = "\n\nThe student with the lowest grade point average is ";

// Creates a string constant to store message for student GPA

final String GPA_MESSAGE = " having GAP: ";

// Creates an object of the Scanner class to open the file for reading

Scanner fileScanner = new Scanner (new File ("students.dat"));

// To store the name read from file and poor student name

String name, poorStudent = null;

// To store the GPA read from file and lowest GPA is assigned to maximum double value constant

double gpa, lowestGPA = MAX_GPA;

// To store the record read from file

Scanner lineScanner = null;

// Loops till end of the file

while (fileScanner.hasNextLine())

{

// Reads a record from file

lineScanner = new Scanner (fileScanner.nextLine());

// Extracts student name

name = lineScanner.next();

// Extracts student GPA

gpa = lineScanner.nextDouble();

// Checks if current GPA read from file is less than the earlier lowestGPA

if (gpa < lowestGPA)

{

// Update the GPA by assigning the current GPA read from the file to lowestGAP

lowestGPA = gpa;

// Update the poor student name by assigning the current student name

// read from the file to poorStudent

poorStudent = name;

} // End of if condition

} // End of while loop

fileScanner.close();

// Checks if lowestGPA is equals to constant MAX_GPA then display the constant error message

if (lowestGPA == MAX_GPA)

System.out.println (NO_VALID_INPUT);

// Otherwise

else

// Display the constant message for student with poor student name with

// GPA constant message with lowest GAP  

System.out.println (BEST_MESSAGE + poorStudent + GPA_MESSAGE + lowestGPA);

} // End of method run

} // End of class LowestGPA

Sample Output:

The student with the lowest grade point average is Rita having GAP: 3.1

Students.dat file contents:

Larry 3.3

Curly 3.7

Moe 3.2

Anil 8.2

Sunil 4.5

Rita 3.1

Gita 7.7