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javawhitespacesymbols

Java unable to recognise special character after space

I have to write a program for the following problem:

enter image description here

I have written the following code:

package secret_message;
import java.util.Scanner;
public class Secret_Message {
    public static void main(String[] args) {
        Scanner sc = new Scanner (System.in);
        int lines, i, codenumber, k;
        String code, codepart, codechar2;
        char codecharacter1, codecharacter2;
        lines = sc.nextInt();
        codepart = "";
        for (i = 1; i<=lines; i++)
        {
            code = sc.next();
            codecharacter1 = code.charAt(0);
            codecharacter2 = code.charAt(1);
            codenumber = Character.getNumericValue(codecharacter1);
            for (k=1; k<=codenumber; k++)
            {
                codechar2 = Character.toString(codecharacter2);
                codepart = codepart + " " + codechar2;
            }
            System.out.println(codepart); 
            codepart = "";
        }
    } 
}

It works perfectly when my input on each line does not have a space (for example if I write "9+" instead of "9 +"). However, on writing "9 +" for example, I get the following error: "String index out of range". I tried changing codecharacter2 = code.charAt(1); in my code to codecharacter2 = code.charAt(2); and codecharacter2 = code.charAt(3); with no success. I also attempted to create a new variable using code.replaceAll("\\s", ""); but this would also remove the "+" in "9 +".

I know it only makes a subtle difference to include the space but the question explicitly states the need for it. Hence, I would appreciate any help on how I can get around this problem!

Solution

  • The problem is here code = sc.next(); this means you are only taking the first token from the input which is the first character. Instead you need to take the entire line as per your logic i.e.,

    code = sc.nextLine();

    Better solution would be to take the integer and character separately. Check below code:

        for (i = 1; i<=lines; i++)
    {
        codenumber= sc.nextInt();
        codechar2 = sc.nextLine().charAt(0);
        for (k=1; k<=codenumber; k++)
        {
            codepart = codepart + " " + codechar2;
        }
        System.out.println(codepart); 
        codepart = "";
    }