How do I get int values out of a string using two scanner objects?

Question

I'm really new to coding and right now I need to take an input from the user in one line seperated by spaces for example "0 1 2" and then take the ints in that string and place them in separate int variables.

This is what I have so far:

Scanner scan = new Scanner(System.in); //takes input from user
input = scan.nextLine();
Scanner intValues = new Scanner(input); //takes input from the "input" variable

then I go to place the first int value into a variable and get a "NoSuchElementException"

int x = intValues.nextInt();

What am I doing wrong here? Also I'm not allowed to use arrays for this assignment.

is using 2 `scanners` necessary ?, because you could avoid all the confusion by using only one — dumbPotato21, Mar 14 '17 at 20:05

score 1 · Answer 1 · answered Mar 14 '17 at 19:51

1

There is no need to use 2 scanner to read the input. You can even achieve this using one scanner. Like this:

Scanner scanner = new Scanner(System.in);
int x = scanner.nextInt();
int y = scanner.nextInt();
int z = scanner.nextInt();

answered Mar 14 '17 at 19:51

Jayesh Doolani

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I dont think so. That would need the user to enter 0, enter, 1, enter, 2, enter, instead of, what he wants, 0, space, 1, space, 2, enter – Luatic Mar 14 '17 at 20:03
2

@user7185318 No it wouldn't. This works fine as it is, provided there are no characters in there that aren't numbers and aren't white space. – Dawood ibn Kareem Mar 14 '17 at 20:05
@DavidWallace : Of course it does so. But have you tested it with the following : `0 1 2` enter ? does this return you x=0, y=1 and z=2 ? – Luatic Mar 14 '17 at 20:07
Yes, it does. Try it. – Dawood ibn Kareem Mar 14 '17 at 20:08

VHS · Answer 2 · 2017-03-14T20:13:35.337

1

You should always use hasNext method on the Scanner class to avoid the NoSuchelementException exception.

Try the following snippet:

    Scanner scan = new Scanner(System.in); //takes input from user
    String input = scan.nextLine();
    Scanner intValues = new Scanner(input); 
    while(intValues.hasNextInt()) {
        int x = intValues.nextInt();
        System.out.println(x);
    }

Or try the following which uses only one scanner:

    Scanner scan = new Scanner(System.in); //takes input from user
    while(scan.hasNextInt()) {
        int x = scan.nextInt();
        System.out.println(x);
    }

edited Mar 14 '17 at 20:13

answered Mar 14 '17 at 19:53

VHS

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I think what you are doing wont work for the case with `0 1 2` and then pressing enter… – Luatic Mar 14 '17 at 20:05
2

better to use hasNextInt here – Patrick Parker Mar 14 '17 at 20:08
@PatrickParker, that's an excellent suggestion. I edited my answer accordingly. thanks much. – VHS Mar 14 '17 at 20:14
Thank you for this answer, but the problem i'm having is that the intValues.nextInt isn't giving me any int values from the string DESPITE the string being literally "0 1 2". The while statement is never true in this case and nothing gets put into x, which is a huge problem for the rest of my code. – Mohd Hasan Mar 14 '17 at 20:23
@MohdHasan, what is your actual input? is it `0 1 2`? – VHS Mar 14 '17 at 20:30
Yes, the actual input im using to test out my code is "0 1 2", which is put into variable "input" I'm trying to put each of the int values, 0 1 and 2 into separate int variables, but i'm running into the issue as I stated above when I try to use a second scanner to get the 3 int values in this string. I understand that this could be done with just one scanner object but the exercise i'm doing wants me to do it this way... – Mohd Hasan Mar 14 '17 at 20:39
@MohdHasan, you need to show your code in that case. I have shown two choices in my answer. Both work fine. – VHS Mar 14 '17 at 20:42

How do I get int values out of a string using two scanner objects?

2 Answers2