title: Java: coding that uses a variable to specify array length?
body: <p>I am working on a student scores application that accepts the last name, first name and score for one or more students and stores the results in an array.  Then it prints the students and their scores in alphabetical order by last name.  We do not know how many students there are, but there will be fewer than 100.</p>
  
  <p>We have to display the class average at the end of the student information and display a message after each student whose grade is more than 10 points below the class average.  </p>
  
  <p>My first issue is that I have created a do/while loop to ask if the user would like to enter another but it will not work!?!?</p>
  
  <p>Second, I can not figure out how to display the "10 points below" message on individual students.</p>
  
  <pre><code>public class Student implements Comparable
  {
      String firstName;
      String lastName;
      int score; 
  
      //stores last name, first name and score for each student
      public Student(String lastName,String firstName,int score)
      {
          this.lastName = lastName;
          this.firstName = firstName;
          this.score = score;    
      }
      //implement the comparable interface so students can be sorted by name
      public int compareTo(Object o)
      {
          Student otherStudent = (Student)o;
  
          if(otherStudent.lastName.equals(lastName))
              {
              return firstName.compareToIgnoreCase(otherStudent.firstName);
              }
          else
              {
              return lastName.compareToIgnoreCase(otherStudent.lastName);
              }
      }
      public String toString()
      {
          return lastName + ", " + firstName + ": " + score; 
      }
  }
  
  import java.util.Scanner;
  import java.util.Arrays;
  
  public class StudentApp
  {
      static Scanner sc = new Scanner(System.in);
  
      public static void main(String [] args)
      {
          Student [] studentArray;
          String lastName;
          String firstName;
          int score = 0;
          double average = 0;
  
  
          System.out.println("Welcome to the Student Scores Application.");
          System.out.println();
  
          do{
  
              //code that uses variable to specify the array length
          int nStudent = 100;  //array size not set unit run time
          studentArray = new Student[nStudent];
  
              for (int i=0; i&lt;nStudent; i++)
              {
              System.out.println();
  
              lastName = Validator.getRequiredString(sc, 
                             "Student " + (i+1) +  " last name: ");
              firstName = Validator.getRequiredString(sc, 
                             "Student " +  " first name: ");               
              score = Validator.getInt(sc, 
                           "Student " + " score: ",
                          -1, 101);
  
              studentArray[i] = new Student(lastName, firstName, score);
  
              double sum = 0.0;
              sum += score;
              average = sum/nStudent;
              }
          }while (getAnotherStudent());
  
          Arrays.sort(studentArray);
  
          System.out.println();
  
          for (Student aStudent: studentArray)
          {
              System.out.println(aStudent);
              if (score&lt;= (average-10))
              {
                  System.out.println ("Score 10 points under average");
              }
          }
          System.out.println("Student Average:" +average);
      }
      public static boolean getAnotherStudent()
      {
          System.out.print("Another student? (y/n): " );
          String choice = sc.next();
          if (choice.equalsIgnoreCase("Y"))
              return true;
          else
              return false;
      }
  }
  </code></pre>