NoSuchElementException while using Scanner to read input

Question

The following Java method is suppose to accept a string (name of a person) from the user via keyboard, search that name in an array called name[] and delete that person's name from the array (by assigning name[i] = "INVALID").

The code tries to accept the input string (the name of the person) using a Scanner class object del_name, but I am getting a NoSuchElementException in the statement

s=del_name.next();

i.e the 4th statement from the top.

I will be really grateful if someone can give a solution and also explain as to why this code is not working. (Thank You)

void Deletee()
{


      Scanner del_name=new Scanner(System.in);

      String s;

      System.out.println("Enter the name to be deleted");

      s=del_name.next(); // causing NoSuchElementException

      int i=0;

   /* find position in which the name occurs using while-loop below */


      while(!s.equalsIgnoreCase(name[i]) && i<count) 

             i++ ;  // increment i to search in next array index



      if(i<count)
      {
          name[i]="INVALID";

          count--;

          System.out.println("Deletion Successful");
      }
      else
      {

          System.out.println("No such person exist");

      }

      del_name.close();


}

Tetramputechture · Answer 1 · 2014-10-18T20:18:13.863

1

Change .next() to .nextLine().

Scanner del_name=new Scanner(System.in);

String s;

System.out.println("Enter the name to be deleted");

s=del_name.nextLine();

Scanner.next() returns whatever the current input is, even if there is none (giving you your error). Scanner.nextLine() skips past the current line, and returns the skipped portion.

edited Oct 18 '14 at 20:18

answered Oct 18 '14 at 20:12

Tetramputechture

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score 0 · Answer 2 · answered Oct 18 '14 at 20:16

Try with,

del_name.nextLine()

Using next() will only return what comes before a space. nextLine() automatically moves the scanner down after returning the current line.

next(): Finds and returns the next complete token from this scanner.
nextLine(): Advances this scanner past the current line and returns the input that was skipped.

score 0 · Answer 3 · answered Oct 18 '14 at 20:40

The code that you posted does not throw an exception as-is. You might have done something prior to this method call that caused this. As proof, run this code:

public class Test {

    static String[] name = new String[] {"AAA", "BBB", "CCC"};

    static void deletee() {

        Scanner delName = new Scanner(System.in);
        System.out.println("Enter the name to be deleted");
        String s = delName.next();

        boolean found = false;
        for (int i = 0; i < name.length; i++) {
            if (name[i].equalsIgnoreCase(s)) {
                name[i] = "INVALID";
                System.out.println("Deletion Successful");
                found = true;
                break;
            }
        }
        if (!found)
            System.out.println("No such person exist");
        delName.close();
    }

    public static void main(String[] args) {

        deletee();
        for (int i = 0; i < name.length; i++)
            System.out.print(name[i] + ", ");
    }
}

Notes:

Method names should start with lower case.
Non-final variables should not use underscores, just uppercases where a new word begins.
I rewrote the searching mechanism for something more intuitive, although there are many more ways to do this.
Good job on closing the scanner.

NoSuchElementException while using Scanner to read input

3 Answers3