Question

I am a beginner in Java and am working on a Mastermind project for a course.

I have a problem. I want to retrieve the value of leftDigit and put it into array guess[4]. But I don’t know how to retrieve it outside the loop.

Let’s say when I input the number 1234 and I want it to become int[] guess = { 1, 2, 3, 4};
`

public static void inputNumber(){   

        Scanner input = new Scanner(System.in);
        currentRow++;

        System.out.printf ("Enter 4 numbers for attempt #%d: ", currentRow);

        int count = 10000, leftDigit;
        double tempNum;

        int number = input.nextInt();


        //finding the left digit   
        do{    
            tempNum = (double) number / count ;  
            leftDigit =  (int) (tempNum * 10) ;         
            count /=10;                         
            number = number - ( count * leftDigit);             
        } while (count != 1 );
    }

Answer 1

The solution which was posted works, but there are a few things that are unnecessary tho. Here’s the code and I’ll explain below:

int count = 1000;                    // notice I start at 1000, not 10_000
int[] guess = new int[4];
int i = 0;

do {
    guess[i++] = number / count;     // (1)
    number %= count;                 // (2)
    count /= 10;
} while (count != 1)

(1): because both number and count are typed int, the result will not be a floating point number and it won’t be rounding up. it’ll just truncate the floating part. For example: 8 / 3 == 2; 543 / 1000 == 0.

(2): This line will get the remainder of the division. For example: 16 % 5 = 1; 1043 % 1000 = 43. (Another way to write this line would be number = number % count).