Question

JAVA program

Note: you can't change anything is already written

Student.java

public class Student {

   private String name;
   private String major;
   private double gpa;

   public Student(String name, String major, double gpa) {
       // TO-DO: Assign the given parameters to the data fields. Use the this keyword.
   }

   public double getGPA() {
       // TO-DO: return this.gpa
   }

   public String getName() {
       // TO-DO: return this.name
   }

   // toString method: this is a handy way to specify what you want it to look like when you
   // print a Student object. Without this, printing a student using System.out.println(student)
   // will print a memory address. The toString method is called implicitly (you don't have to
   // call it explicitly when you print)
   public String toString() {
       return "[" + name + ", " + major + ", " + gpa + "]";
   }

}

StudentShuffle.java

/* Your Name
* Date
* Homework 3 – StudentShuffle
*/

import java.util.Scanner;
import java.io.*;

public class StudentShuffle {

   private Student[] studentArray;

   public StudentShuffle() {
       this.studentArray = new Student[15];
   }

   public Student[] getStudentArray() {
       return this.studentArray;
   }

   public void getDataFromFile() {
       /* TO-DO: write a method to get data from the text file, store the data in
       * Student objects, and store the students in an array.
       * Suggestion: use Scanner myScanner = new Scanner(new FileReader("students_list.txt"))
       * to access the file.
       * Write your code inside the try block (you can leave the catch block as-is).
       * Some useful methods: Scanner hasNextLine(), String split(), Double.valueOf()
       */
      
       // You may initialize some variables here
      
       try {
          
           // Your code here

       } catch(FileNotFoundException e){
           System.out.println(e.getMessage());
       }
   }

   public void printStudents(Student[] students) {
       // TO-DO: write code to print each student on a new line.
       // The toString method in Student class is already written, so
       // using system.out.println(students[i]) will print a student using my format
       // NOTE: you must not display null values
      
       // Your code here
   }

   public double findLowestGPA() {
       // TO-DO: write a method to find the lowest GPA and return that value.
       // Make sure to write logic to handle null values in the array.
       // Hint: use the method getGPA from Student class

       // Your code here

   }

   public Student[] getStudentsWithPerfectGPA() {
       // TO-DO: write code that finds the students with perfect GPA (4.0),
       // adds those students to a new array, and returns that array
       // Hint: use the method getGPA from Student class
      
       // Your code here

   }

   public Student[] sortAlphabetically(Student[] students) {
       // BONUS: write code to sort the student array alphabetically by name from A -> Z.
       // I suggest creating a new array so as to not modify the original (although this
       // is not required).
       // You may use any sorting algorithm, as long as you implement it yourself.
       // Hints: use getName() method from Student class, compareTo method.
       // Be sure to deal with null values in the array.
      
       // Your code here

   }

   public static void main(String[] args) {
       // TO-DO: implement your main method (see notes below)

       System.out.println("\nPart1 - Get data from file and print students");
       System.out.println("------------------------------------------------");
       // Instantiate a StudentShuffle object.
       // Call the method getDataFromFile() using the StudentShuffle object,
       // for example shuffle.getDataFromFile().
       // Call shuffle.printStudents(shuffle.getStudentArray()) to print the students
      

       System.out.println("\nPart2 - Find the lowest GPA value");
       System.out.println("------------------------------------------------");
       // Call findLowestGPA() method, save the value returned, and print it
      

       System.out.println("\nPart3 - Find the students with highest GPA");
       System.out.println("------------------------------------------------");
       // Call getStudentsWithPerfectGPA() method, save the returned array,
       // and use your printStudents method to print the good students
      

       System.out.println("\nPart4 Bonus - Sort the students alphabetically");
       System.out.println("------------------------------------------------");
       // Call your sortedAlphabetically method and save the returned array.
       // Use your printStudents method to print the sorted array.
      
   }

}

Student_list.text

Brenna Computer_Science 4.0
Janet Biology 3.4
Sandeep Physics 3.9
Grant Marketing 4.0
Wei Business 3.7
Andre Communications 3.7
Fernanda Math 3.9
Jonas Physiology 2.9
Grace Fine_arts 3.5
Stephanie Chemistry 4.0
Mohammed Business 3.9
Nozomi Computer_Science 3.5
Aparna Literature 3.7
Ayesha Business 3.5

1- you need to get data from file

2- print the data

3- print the lowest gpa

4- print student with gpa 4.0

5- sort Alphabetically and print them

Answer 1

Note: Everything is done and tested...If you need any help feel free to comment.

Please UPRATE.

Thanks.

StudentShuffle.java

package StudentShuffle;

import java.util.Arrays;
import java.util.Comparator;

/* Your Name
* Date
* Homework 3 – StudentShuffle
*/

import java.util.Scanner;
import java.io.*;

public class StudentShuffle {

private Student[] studentArray;

public StudentShuffle() {
this.studentArray = new Student[15];
}

public Student[] getStudentArray() {
return this.studentArray;
}

public void getDataFromFile() {
/* TO-DO: write a method to get data from the text file, store the data in
* Student objects, and store the students in an array.
* Suggestion: use Scanner myScanner = new Scanner(new FileReader("students_list.txt"))
* to access the file.
* Write your code inside the try block (you can leave the catch block as-is).
* Some useful methods: Scanner hasNextLine(), String split(), Double.valueOf()
*/
  
// You may initialize some variables here
   String[] arrOfStr;
   String line,name,major;
   double gpa;
   int index=0;
   Scanner myScanner = null;
   try {
       myScanner = new Scanner(new FileReader("students_list.txt"));
           while(myScanner.hasNextLine()){
               line = myScanner.nextLine();
               arrOfStr = line.split(" ");
               if(arrOfStr.length == 3){
                   name = arrOfStr[0];
                   major = arrOfStr[1];
                   gpa =Double.parseDouble(arrOfStr[2]);
                   Student stdObj=new Student(name,major,gpa);
                   studentArray[index] = stdObj;
                   index++;
                   //System.out.println(stdObj.toString());
               }
           }
   } catch (FileNotFoundException e1) {
       // TODO Auto-generated catch block
       e1.printStackTrace();
   }finally{
       if(myScanner!=null)
           myScanner.close();
   }
}

public void printStudents(Student[] students) {
// TO-DO: write code to print each student on a new line.
// The toString method in Student class is already written, so
// using system.out.println(students[i]) will print a student using my format
// NOTE: you must not display null values
  
// Your code here
   for(Student x:students){
       if(x!=null)
       System.out.println(x.toString());
   }
}

public double findLowestGPA() {
// TO-DO: write a method to find the lowest GPA and return that value.
// Make sure to write logic to handle null values in the array.
// Hint: use the method getGPA from Student class

// Your code here
   double lowestGpa=1000;
   for(Student x : studentArray){
       if(x!=null){
           if(x.getGPA()<lowestGpa)
           {
               lowestGpa=x.getGPA();
           }
       }
   }
   if(lowestGpa!=1000)
   return lowestGpa;
   else
       return 0;

}

public Student[] getStudentsWithPerfectGPA() {
// TO-DO: write code that finds the students with perfect GPA (4.0),
// adds those students to a new array, and returns that array
// Hint: use the method getGPA from Student class
     
// Your code here
   int countPerfect=0;
   int index=0;
   for(Student x : studentArray){
       if(x!=null && x.getGPA()==4)
       {
           countPerfect++;   
       }
   }
   Student[] student=new Student[countPerfect];
   for(Student x : studentArray){
       if(x!=null && x.getGPA()==4)
       {
           student[index]=x;
           index++;
       }
   }
   return student;
}

public Student[] sortAlphabetically(Student[] students) {
// BONUS: write code to sort the student array alphabetically by name from A -> Z.
// I suggest creating a new array so as to not modify the original (although this
// is not required).
// You may use any sorting algorithm, as long as you implement it yourself.
// Hints: use getName() method from Student class, compareTo method.
// Be sure to deal with null values in the array.
  
// Your code here
   Student[] tempArray=students;
   Arrays.sort(tempArray, new Comparator<Student>() {
       public int compare(Student s1, Student s2) {
           if (s1 == null && s2 == null) {
       return 0;
       }
       if (s1 == null) {
       return 1;
       }
       if (s2 == null) {
       return -1;
       }
       return s1.getName().compareTo(s2.getName());
       }
       });
   return tempArray;
}

public static void main(String[] args) {
// TO-DO: implement your main method (see notes below)

System.out.println("\nPart1 - Get data from file and print students");
System.out.println("------------------------------------------------");

// Instantiate a StudentShuffle object.
StudentShuffle shuffle=new StudentShuffle();
// Call the method getDataFromFile() using the StudentShuffle object,
// for example shuffle.getDataFromFile().
shuffle.getDataFromFile();
// Call shuffle.printStudents(shuffle.getStudentArray()) to print the students
shuffle.printStudents(shuffle.getStudentArray());

System.out.println("\nPart2 - Find the lowest GPA value");
System.out.println("------------------------------------------------");
// Call findLowestGPA() method, save the value returned, and print it
System.out.println(shuffle.findLowestGPA());

System.out.println("\nPart3 - Find the students with highest GPA");
System.out.println("------------------------------------------------");
// Call getStudentsWithPerfectGPA() method, save the returned array,
// and use your printStudents method to print the good students
Student[] tempArray=shuffle.getStudentsWithPerfectGPA();
shuffle.printStudents(tempArray);

System.out.println("\nPart4 Bonus - Sort the students alphabetically");
System.out.println("------------------------------------------------");
// Call your sortedAlphabetically method and save the returned array.
// Use your printStudents method to print the sorted array.
Student[] tempArray2=shuffle.sortAlphabetically(shuffle.getStudentArray());
shuffle.printStudents(tempArray2);
}

}

Student.java :

package StudentShuffle;

public class Student {

private String name;
private String major;
private double gpa;

public Student(String name, String major, double gpa) {
// TO-DO: Assign the given parameters to the data fields. Use the this keyword.
   this.name =name;
   this.major=major;
   this.gpa=gpa;
}

public double getGPA() {
   // TO-DO: return this.gpa
   return gpa;
}

public String getName() {
// TO-DO: return this.name
   return name;
}

// toString method: this is a handy way to specify what you want it to look like when you
// print a Student object. Without this, printing a student using System.out.println(student)
// will print a memory address. The toString method is called implicitly (you don't have to
// call it explicitly when you print)
public String toString() {
return "[" + name + ", " + major + ", " + gpa + "]";
}

}

Output :