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Thread: Code is ignoring the read.

  1. #1
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    Default Code is ignoring the read.

    As you can see there is a prompt at the very bottom of this code, The prompt is followed by a read. The code skips the read and ends instead, why is this?
    public class Song
    {
     
       static Scanner keyboard = new Scanner (System.in);
     
       public static void main(String[] args)
       {
          Double songDuration;
          String songTitle, songRemove;
          String [] songs = new String[10];
          double  [] songDurations = new double[10];
     
          for (int count=1; count<=9; count++)
          {
             System.out.println("Please enter song title number " + count);
             songTitle=keyboard.nextLine();
             songs[count] = songTitle;
          }
     
          for (int count=1; count<=9; count++)
          {
             System.out.println("Song Number " + count + " = " + songs[count]);
     
          }
     
          for (int count=1; count<=9; count++)
          {
             System.out.println("Please enter duration of song " + songs[count]);
             songDuration=keyboard.nextDouble();
             songDuration=songDurations[count];
     
          }
     
          System.out.println("What song title would you like to remove from the array?");
          songRemove=keyboard.nextLine();


  2. #2
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    Default Re: Code is ignoring the read.

    The code skips the read and ends instead
    The posted code doesn't show anything after the read.
    How do you know that the read was skipped? What if the read read an empty line? Did you print out what was read to see? Add a println after the read that shows what was read into the variable.

    This sounds like the Scanner problem when the code calls nextLine() following a call to one of the other next methods which leave the lineend character in the Scanner's buffer.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Code is ignoring the read.

    Yes I know, but I am testing as I go along, I know (well, I think) it has ignored it because the console displays the question then a space then 'Process finished with exit code 0'. It does not let me enter info under the question. Just so that we are both on the same boat, I am talking about this
     
          System.out.println("What song title would you like to remove from the array?");
          songRemove=keyboard.nextLine();

  4. #4
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    Default Re: Code is ignoring the read.

    Print out the contents of songRemove after the read to see what is in it. I suspect it will be an empty String.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Code is ignoring the read.

    Yes it just creates an extra empty space .

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    Default Re: Code is ignoring the read.

    That's the Scanner problem when the code calls nextLine() following a call to one of the other next methods which leave the lineend character in the Scanner's buffer.
    You need to call nextLine() one time to read the lineend character that was left in the buffer before trying to read another line.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Code is ignoring the read.

    Could you explain this in a more simple way, sorry

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    Default Re: Code is ignoring the read.

    Add an extra call to nextLine() after a call to nextDouble() and before a call to the nextLine() method where you want to read a line.
    The extra call to nextLine() will read the endline character left in the buffer from when the user pressed Enter to give data to the nextDouble() method.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Code is ignoring the read.

    Thank you

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