Java Scanner Input Loop

Question

I've got a loop that is controlled by a variable called running which tells if the program is running or not. I am trying to achieve a loop that the user enters a command, and the program is answering him, but for some reason, It's seems like my String splits if its more than one word, this is what I have tried:

import java.util.Scanner;
public class ScannerTest{
    private boolean running = true;
    public ScannerTest(){
        Scanner s = new Scanner(System.in);
        while(running){
           String command = s.next();
           System.out.println(command);
        }
    }
}

If I am entering two or more words in the Scanner, It seems to split them.

Input  >> Hello what's your name?
Output >> Hello
       >> what's
       >> your
       >> name?

Maybe it's because of the While loop? How can i fix it? Thanks in advance.

score 4 · Accepted Answer · answered Oct 20 '13 at 20:48

Scanner#next() does just this -- it grabs the next token defined by any white-space delimiter(s), and does not get the next line. If your words have white space between them, it will grab the individual words one at a time with each invocation of the method.

Use Scanner#nextLine() instead if you want to grab the complete line that the user entered.

Edit: this question has to be a duplicate of another somewhere on this site.

Prabhakaran Ramaswamy · Answer 2 · 2013-10-20T20:55:58.003

0

next() method will split your input by space delimiter.

nextLine() method will fix your problem. nextLine(); will read the entire line at once.

Replace String command = s.next(); to String command = s.nextLine();

edited Oct 20 '13 at 20:55

answered Oct 20 '13 at 20:49

Prabhakaran Ramaswamy

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But how does this work if you need to get integer inputs in a loop? I noticed that nextInt seems to skip an input because of a RETURN character (I presume). – itsols Nov 12 '14 at 12:42

score 0 · Answer 3 · answered Apr 09 '15 at 22:48

0

You're using

System.out.println();

just use

System.out.print();

only use println if you want the next output/input to be entered onto the next line.

answered Apr 09 '15 at 22:48

Mazino

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score 0 · Answer 4 · edited May 23 '17 at 12:24

0

Why don't you use end-of-file indicator, the loop you used in your solution is called sentinel-controlled repetition the I think the better value to control it is by using end-of-file indicator take look at my answer java Scanner.hasNext() usage

edited May 23 '17 at 12:24

Community

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answered Feb 09 '17 at 08:02

Basheer AL-MOMANI

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Java Scanner Input Loop

4 Answers4