CODEWITHSUNDEEP
javaloops
Destroycontract
Destroycontract

Reputation: 21

Loop doesn't recognise a changing variable

I am trying to ask the user if they want to continue inputting numbers to add to a total value

    int total=0; 

    char letter='y';

    while (letter == 'y');
    {
            Scanner userInput = new Scanner (System.in);
            System.out.println("Input your number");
            int number = userInput.nextInt();

            total=number+total;


            Scanner userInput1 = new Scanner (System.in);
            System.out.println("Would you like to continue? Input y/n");
            char letter = userInput1.next().charAt(0); //**This is where there is an error**

    }        
    System.out.println("The total of all the numbers inputted is "+total);
    }
}

Upvotes: 1

Views: 59

Answers (3)

SOFe
SOFe

Reputation: 8214

  1. You shouldn't have the ; on line 5 (the while line).
  2. It is more performance-efficient to initialize the Scanner only once, outside the loop.
  3. On the last line in the loop, use letter = *** instead of char letter = ***. You already declared the variable letter.
  4. Perhaps you should handle the nextInt line in case user typed a non-number.

Possible improvement:

int total=0;
char letter='y';
Scanner userInput = new Scanner(System.in);
while(letter == 'y')
{
    System.out.println("Input your number");
    int number = userInput.nextInt();
    total += number;
    System.out.println("Woud you like to continue? Input y/n");
    letter = userInput.next().charAt(0);
}

Upvotes: 2

Davide Lorenzo MARINO
Davide Lorenzo MARINO

Reputation: 26926

Simply remove char, because letter was already defined. Instead of

char letter = userInput1.next().charAt(0);

write 

// char removed
letter = userInput1.next().charAt(0);

And also as Pemap said remove the ; after the while

Basically your code should be similar to the following

while (letter == 'y') {
        Scanner userInput = new Scanner (System.in);
        System.out.println("Input your number");
        int number = userInput.nextInt();

        total = number + total;


        Scanner userInput1 = new Scanner(System.in);
        System.out.println("Would you like to continue? Input y/n");
        letter = userInput1.next().charAt(0); 
}

Upvotes: 1

Faraz
Faraz

Reputation: 6265

2 problems. 1st) you have a ; in a while statement line. 2nd) you have already declared letter variable. No need to declare it again after asking for input the 2nd time. Hope it helps. 

int total=0; 
char letter='y';
while (letter == 'y')
{
        Scanner userInput = new Scanner (System.in);
        System.out.println("Input your number");
        int number = userInput.nextInt();

        total=number+total;


        Scanner userInput1 = new Scanner (System.in);
        System.out.println("Would you like to continue? Input y/n");
        letter = userInput1.next().charAt(0); //**This is where there is an error**
}        
System.out.println("The total of all the numbers inputted is "+total);
}
}

Upvotes: 1

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