Question

Write a Java program that sorts an array of “Student” in an aescending order of their “last names”. The program should be able to apply (bubble sort):

Student [] studs = new Student[8];

s[0] = new Student("Saoud", "Mohamed", 3.61);

s[1] = new Student("Abdelkader", "Farouk", 2.83);

s[2] = new Student("Beshr" , "Alsharqawy", 1.99);

s[3] = new Student("Nader", "Salah", 3.02);

s[4] = new Student("Basem", "Hawary", 2.65);

s[5] = new Student("Abdullah", "Babaker", 2.88);

s[6] = new Student("Abdelaal", "Khairy", 3.13);

s[7] = new Student("Mohamedain", "Marsily", 4.00);

Answer 1

Code:

class Student//student class
{
   String firstname, lastname;double gpa;
   public Student(String firstname, String lastname, double gpa)//constructor
   {
       this.firstname = firstname;this.lastname = lastname;this.gpa = gpa;
   }
   public String getFirstName()//getter methods
   {
       return firstname;
   }
   public String getLastName()
   {
       return lastname;
   }
   public double getGPA()
   {
       return gpa;
   }
   public void setFirstName(String firstname)//setter methods
   {
       this.firstname = firstname;
   }
   public void setLastName(String lastname)
   {
       this.lastname = lastname;
   }
   public void setGPA(double gpa)
   {
       this.gpa = gpa;
   }
}
public class A
{
   public static void main(String args[])
   {
       Student []studs = new Student[8];int i, j, n=8;//n holds no of objects
       studs[0] = new Student("Saoud", "Mohamed", 3.61);//creating objects
       studs[1] = new Student("Abdelkader", "Farouk", 2.83);
       studs[2] = new Student("Beshr" , "Alsharqawy", 1.99);
       studs[3] = new Student("Nader", "Salah", 3.02);
       studs[4] = new Student("Basem", "Hawary", 2.65);
       studs[5] = new Student("Abdullah", "Babaker", 2.88);
       studs[6] = new Student("Abdelaal", "Khairy", 3.13);
       studs[7] = new Student("Mohamedain", "Marsily", 4.00);
       for(i=0;i<n-1;i++)//bubble sort
       {
           for(j=0;j<n-i-1;j++)
           {
               if((studs[j].getLastName()).compareTo(studs[j+1].getLastName()) > 0)
               {
                   String f = studs[j].getFirstName();//swap object studs[j]'s contents with that of object studs[j+1]
                   String l = studs[j].getLastName();
                   double g = studs[j].getGPA();
                   studs[j].setFirstName(studs[j+1].getFirstName());
                   studs[j].setLastName(studs[j+1].getLastName());
                   studs[j].setGPA(studs[j+1].getGPA());
                   studs[j+1].setFirstName(f);
                   studs[j+1].setLastName(l);
                   studs[j+1].setGPA(g);
               }
           }
       }
       System.out.println("After sorting:");
       for(i=0;i<n;i++)
       {
           System.out.println(studs[i].getFirstName() + " " + studs[i].getLastName() + " " + studs[i].getGPA());
       }
   }
}

Output: