Java splitting input

Question

i'm trying to write a simple code for my project if user types

walk 10

i need to use "walk" command in my walk(distance) method as distance = 10 i have something like that

while (!quit) {
Scanner in = new Scanner(System.in);
String input = in.nextLine();
// if (walk x is typed) {
walk(x);
}
}

i'm using java.util.scanner and another problem is that my method walk(int x) uses int so i need to convert String input to int

i searched the web for a while but couldnt find what i'm looking for (or i didnt understand it)

so anyway i'd appreciate if you can help me thanks

Thanks a lot for all the answers my initial problem is fixed but now i have another problem when i type just "walk" it gets array out of bounds exception of course because it tries to convert null to an int (not possible) i tried this and checked online

                    try {
                    Integer.parseInt(splitStrings[1]);
                    }
                    catch(NumberFormatException e) {
                    System.out.println("error: " + e);
                    }

still no help (i'm not good with try/catches) so if user types walk without a distance i need to give an error message thanks a lot again

ok i got it too just used a simple thing

            if ("walk".equals(splitStrings[0])) {
                if (splitStrings.length == 2) {
                int distance = Integer.parseInt(splitStrings[1]);
                Robot.walk(distance);
                }
                if (splitStrings.length != 2) {
                    System.out.println("Entry must be like walk 10");
                }
            }

Solution 1

Try using the split() method on a string. It will return an array of Strings. For example

String s = 'walk 10';
String[] splitStrings = s.split(" ")

Now, to access 10, you can do this:

String distanceToWalk = splitStrings[1]

To convert it to an int, use the parseInt() method on Integer

Integer.parseInt(distanceToWalk);

See

1. http://docs.oracle.com/javase/6/docs/api/java/lang/String.html#split%28java.lang.String%29
2. http://docs.oracle.com/javase/6/docs/api/java/lang/Integer.html#parseInt%28java.lang.String%29

Solution 2

You can split on the space, in which case the number would be the second element (index 1) of the resulting array e.g.

Edit following comment from Adam Liss

Integer x = Integer.parseInt(input.split(" ")[1])

Solution 3

You can use the Integer.parseInt() method:

int distance = Integer.parseInt(input);

Comments

[mikera]

+1 for a neat solution, though given that this is user input you would also want to strip out excess spaces first (otherwise your number will be in the wrong place in the array).

[Adam Liss]

Wait, what??? You can't cast a String to an Integer! Shame on all you upvoters.

[Berk Kalkavan]

thanks a lot. that was exactly what i was looking for both splitting the input in 2 from white space and converting 10 to integer

[Martin]

@AdamLiss You are absolutely correct, modified the answer accordingly.

[Adam Liss]

@Strawberry +1 for updating. Also for the audacity to post an answer that wasn't even valid Java ... and still managing to get 3 upvotes!

[Berk Kalkavan]

how can i use tokenizer with java.util.scanner?

[Paul Vargas]

I added for StringTokenizer and Scanner.