Question

I want to separate the elements of a text file into different arrays based of whether or not the line contains a question mark. Here is as far as I got.

    Scanner inScan = new Scanner(System.in);

    String file_name;
    System.out.print("What is the full file path name?\n>>");
    file_name = inScan.next();

    Scanner fScan = new Scanner(new File(file_name));
    ArrayList<String> Questions = new ArrayList();
    ArrayList<String> Other = new ArrayList();

    while (fScan.hasNextLine()) 
    {
        if(fScan.nextLine.indexOf("?"))
        {
            Questions.add(fScan.nextLine());
        }

        Other.add(fScan.nextLine());
    }

Answer 1

Quite a few issues there

• nextLine() actually returns the next line and moves on the scanner, so you’ll need to read once instead
• indexOf returns an int, not a boolean, I’m guessing you’re more use to C++? You can use any of the following instead:
  • indexOf(“?”) >=0
  • contains(“?”)
  • matches(“\?”) etc.
• please follow the java ways and use camelCase for vars…

Code

public static void main(String[] args) throws FileNotFoundException {

    Scanner scanner = new Scanner(new File("foo.txt"));
    List<String> questions = new ArrayList<String>();
    List<String> other = new ArrayList<String>();
    while (scanner.hasNextLine()) {
        String line = scanner.nextLine();
        if (line.contains("?")) {
            questions.add(line);
        } else {
            other.add(line);
        }
    }
    System.out.println(questions);
    System.out.println(other);
}

foo.txt

line without question mark
line with question mark?
another line