java - Checking input type...how?

Question

I have the following method:

public void addStudent(){

    String fName, lName;
    double mGrade, fGrade;
    System.out.print("
Enter first name: ");
    Scanner in = new Scanner(System.in);
    fName = in.nextLine();
    System.out.print("
Enter last name: ");
    lName = in.nextLine();
    System.out.print("
Enter midterm grade: ");
    mGrade = in.nextDouble();
    System.out.print("
Enter final grade: ");
    fGrade = in.nextDouble();
    Student toAdd = new Student(fName, lName, mGrade, fGrade);
    students.add(toAdd);
    System.out.println("
Student record added.
");
    System.out.println(students.size());
}

How can I check if the user typed in something other than an integer for midterm grade and final grade? And if they entered a non-integer, I want the method to just request the user type in that value again. I'm guessing I'll have to use a do-while loop. But I don't don't know how to check the type...

Thanks!

Answer 1

You can use Scanner.next() and try to parse it to the type you want (ex. to integer by using Integer.parseInt(x) and if it fails (throws and exception) try to do it again.