When code repeats from a loop, user input option is lost

Question

For some reason unknown to me, when my code loops back to the start some string input option is lost.. here is my problem.

Enter student's name: 
Bob
Enter student's subject: 
Maths
Enter student's number: 
12345
Enter level student last completed (0-3): 
0
Would you like to enter data for another student? Yes/No 
Yes
Enter student's name: 
Enter student's subject: 
English        
Enter student's number: 
55677
Enter level student last completed (0-3): 
0

as you can see when the loop goes round again to allow the user to enter the details again it just prints out

Enter student's name: 
Enter student's subject: 
English        
Enter student's number: 
55677
Enter level student last completed (0-3): 
0

simultaneously, and only allows input for the subject not the name, skipping the input option for student name. The fields after that work as normal though.

Here is my code

    import java.util.*;

public class StudentData 
{
    public static void main(String[] args) 
    {
        Scanner in = new Scanner(System.in);
        ArrayList<Student> studentList = new ArrayList<Student>();
        String yesNo; // = "true";
        int level = 0;

        do
        {
            int averageResult = 0;
            int result1 = 0;
            int result2 = 0;
            int result3 = 0;

//          in.next();
            System.out.println("Enter student's name: ");
            String name = in.nextLine();
            System.out.println("Enter student's subject: ");
            String subject = in.nextLine();
            System.out.println("Enter student's number: "); 
            int number = in.nextInt();

            do
            {
                System.out.println("Enter level student last completed (0-3): "); 
                 level = in.nextInt();
                }
            while (level > 3 || level < 0);
            if (level > 0)
            {
                if (level == 3)
                {
                System.out.println("Enter result for level 3: "); 
                result3 = in.nextInt();
                System.out.println("Enter result for level 2: "); 
                result2 = in.nextInt();             
                System.out.println("Enter result for level 1: "); 
                result1 = in.nextInt();
                }
            else if (level == 2)
            {
                System.out.println("Enter result for level 2: "); 
                result2 = in.nextInt();
                System.out.println("Enter result for level 1: "); 
                result1 = in.nextInt(); 
                }   
            else if (level == 1)    
            {
                System.out.println("Enter result for level 1: "); 
                result1 = in.nextInt();
                }

//          averageResult = 0;
            averageResult= ((result1 + result2 + result3) / level); 
            }
//          System.out.println(averageResult); 
            else
            {

            }
            Student s = new Student(name,subject,number,level,result1,result2,result3,averageResult);   
            studentList.add(s);



            do
            {   
                System.out.println("Would you like to enter data for another student? Yes/No ");
                yesNo = in.next();
                }
            while (!yesNo.equalsIgnoreCase("YES") && !yesNo.equalsIgnoreCase("NO"));
            }   
        while (yesNo.equalsIgnoreCase("YES"));




        for(int i = 0; i < studentList.size(); i++)
        {
            System.out.println("Student's name: "+studentList.get(i).getName());
            System.out.println("Student's subject: "+ studentList.get(i).getSubject());
            System.out.println("Student number: "+studentList.get(i).getNumber());
            System.out.println("Level which student has completed: "+studentList.get(i).getLevel());
            System.out.println("Result for level 1:"+studentList.get(i).getResults1());
            System.out.println("Result for level 2:"+studentList.get(i).getResults2());
            System.out.println("Result for level 3:"+studentList.get(i).getResults3());
            System.out.println("Average result for all completed levels: "+studentList.get(i).getAverageResults());
            System.out.println();
            }
        }
    }

How can i allow for input for student name once it loops? Thanks

score 0 · Answer 1 · answered Dec 03 '13 at 18:56

I had the same problem before.I think it's the problem with scanner's nextLine() method. one simple way to fix this problem is to duplicate using nextLine() method where you encounter the problem or you can use another object for taking input from user.

score 0 · Answer 2 · answered Dec 03 '13 at 19:10

0

Rather than using nextLine() to get the name and subject you can use next() would solve your problem

answered Dec 03 '13 at 19:10

user3054341

1

score 0 · Accepted Answer · answered Dec 03 '13 at 19:16

do following change and it will work as expected

Scanner in; //do not create Scanner instance here
ArrayList<Student> studentList = new ArrayList<Student>();
String yesNo; // = "true";
int level = 0;

do
{
    in = new Scanner(System.in);//instead create here

When code repeats from a loop, user input option is lost

3 Answers3