import java.util.HashMap;

import java.util.Map;

import java.util.Scanner;

public class HashMapPractice {

public static void main(String[] args) {

HashMap<String, Double> students = new HashMap<>();

Scanner input = new Scanner(System.in);

String newStudent;

System.out.println("Enter your students (or ENTER to finish):");

// Get student names and grades

do

{

System.out.print("Student: ");

newStudent = input.nextLine();

if (!newStudent.isEmpty()) {

System.out.print("Id: ");

Double newId = input.nextDouble();

students.put(newStudent, newId);

// Read in the newline before looping back

input.nextLine();

}

} while(!newStudent.isEmpty());

// Print class roster

System.out.println("\nClass roster:");

double sum = 0.0;

for(

Map.Entry<String, Double> student :students.entrySet())

{

System.out.println(student.getKey() + " (" + student.getValue() + ")");

sum += student.getValue();

}

double avg = sum / students.size();

System.out.println("Average grade: "+avg);

}

}