Where to close this `input` Scanner?

Question

package game1;
import java.util.Scanner;

public class toothpicks {

    private int number;
    public int HowMany()
    {
        do
        {
            System.out.print("Enter the No. of ToothPicks = ");
            Scanner input =new Scanner(System.in);
            number = input.nextInt(); 
            if(number<4)
            {
                System.out.print("ToothPicks Should be greater than 3\n");

            }

        }while(number<4);

        return number;
    }
}

Where can I close the input Scanner in my program? It giving me error if I close it in the end of the Program just before return statment says input can not be resolved but if I close it in the loop then I cannot achieve what i'm trying to by using this HowMany Method? What to do ? Any help would be appreciated

score 2 · Accepted Answer · answered Aug 22 '15 at 22:02

2

You are creating a new instance of Scanner on each loop. You don't need to, though, so you can just do

Scanner input = new Scanner(System.in);
// do while loop goes here

And then close the Scanner just before the return statement.

answered Aug 22 '15 at 22:02

eric.m

1,577
10
20

Can u tell me why we ever wanna close the scanner? – sony Aug 22 '15 at 22:09
2

http://stackoverflow.com/questions/5919143/is-it-safe-not-to-close-a-java-scanner-provided-i-close-the-underlying-readable – eric.m Aug 22 '15 at 22:11

score 1 · Answer 2 · answered Aug 22 '15 at 22:04

You can declare your Scanner out of the loop (look that you are creating a new instance of Scanner each time the loop make an iteration)

package game1;
import java.util.Scanner;

public class toothpicks {

 private int number;
    public int HowMany()
    {
        Scanner input =new Scanner(System.in);

        do
        {
            System.out.print("Enter the No. of ToothPicks = ");

            number = input.nextInt(); 
            if(number<4)
            {
                System.out.print("ToothPicks Should be greater than 3\n");

            }

        }while(number<4);

        input.close();

        return number;
    }
}

And then close it before the return statement.

I expect it will be helpful for you!

score 1 · Answer 3 · answered Aug 22 '15 at 22:06

1

Define and initialise input and number before the do loop, and close it immediately after the do loop.

answered Aug 22 '15 at 22:06

Dodo

323
1
8

Where to close this `input` Scanner?

3 Answers3