Scanner, useDelimiter

Question

I encounter some problem when using useDelimiter from the Scanner class.

Scanner sc = new Scanner(System.in).useDelimiter(\"-\");
while(sc.hasNext())
{
    S         


        

Answer 1

How I would do it follows:

Scanner stdin = new Scanner(System.in);
String s = stdin.nextLine();
String[] splitInput = s.split("-", -1);

You will now have an array of Strings that contain the data between all of the -s.

Answer 2

You could use an alternative delimiter string useDelimiter( "-|\n" ); It works with a String argument as well as by reading from System.in. In case of System.in this requires you to press enter at the end of the line.

Answer 3

If the Scanner didn't wait for you to enter another - then it would erroneously assume that you were done typing input.

What I mean is, the Scanner must wait for you to enter a - because it has no way to know the length of the next input.

So, if a user wanted to type A-B-CDE and you stopped to take a sip of coffee at C, it woud not get the correct input. (You expect [ A, B, CDE ] but it would get [ A, B, C ])

When you pass it in a full String, Scanner knows where the end of the input is, and doesn't need to wait for another delimiter.

How I would do it follows:

Scanner stdin = new Scanner(System.in);
String input = stdin.nextLine();
String[] splitInput = input.split("-", -1);

You will now have an array of Strings that contain the data between all of the -s.

Here is a link to the String.split() documentation for your reading pleasure.