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Thread: Scanner.useDelimiter("\n") Problem

  1. #1
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    Default Scanner.useDelimiter("\n") Problem

    Hey guys I am having some trouble when I use Scanner.UseDelimeter("\n") basically I have:

    Scanner s = new Scanner(System.in);
              s.useDelimiter("\n");
     
              int amount;
     
              System.out.println("Enter the amount needed: ")
              amount = s.nextInt();


    After I enter the integer for the amount, the program crashes. I use the delimiter for the scanner as I am using scanner.NextLine() later in the program.

    Thanks


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Scanner.useDelimiter("\n") Problem

    the program crashes.
    Please copy and paste the full text of the error message here.

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    Default Re: Scanner.useDelimiter("\n") Problem

    Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Unknown Source)
    at java.util.Scanner.next(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)
    at DessertManager.main(DessertManager.java:39)

    Line 39 is amount = s.nextInt();

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    Default Re: Scanner.useDelimiter("\n") Problem

    java.util.InputMismatchException
    This says that the input being read was not an integer.
    What did you type into the console that caused this?

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    Default Re: Scanner.useDelimiter("\n") Problem

    Just the number 1.

    If I remove the s.useDelimiter("\n");

    There is no problems, but I was told to use this to solve another problem, which is using nextLine() before a nextInt().

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    Default Re: Scanner.useDelimiter("\n") Problem

    I guess using the \n changes the way Scanner works.
    Here is what I tried and what I got:

           Scanner s = new Scanner(System.in);
           s.useDelimiter("\n");  //<<<<<<<<<<
           System.out.println("Enter the amount needed: ");
           System.out.println("hasNextInt=" + s.hasNextInt() + ", hasNext="  + s.hasNext());
           String line = s.nextLine();
           System.out.println("line=" + line + "<");
    /*
          D:\JavaDevelopment\Testing\ForumQuestions6>java TestCode5
          Enter the amount needed:
          1 2 the end
          hasNextInt=false, hasNext=true
          line=1 2 the end<
    */

  7. #7
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    Default Re: Scanner.useDelimiter("\n") Problem

    Yeah the \n changes it. I might just not use it, and use my other solution to the problem I was having. Appreciate your help anyway!

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