Question

How to convert an array of digits to an integer add 1 and convert it back to an array of digits in Java

Answer 1

import java.util.Arrays;

public class Program {
    public static int convertArrayOfDigitsToIntNumber(int[] arr) {
        int n = 0;
        
        for (int digit : arr) {
            n = n * 10 + digit;
        }
        
        return n;
    }

    public static void convertIntNumberToArrayOfDigits(int[] digits, int n) {
        int i = digits.length - 1;
        
        while (n > 0) {
            digits[i] = n % 10;
            n /= 10;
            i--;
        }
    }

    public static void main(String[] args) {
        int[] arr = {9, 4, 6, 9};
        
        int n = convertArrayOfDigitsToIntNumber(arr);
        
        n++;
        
        convertIntNumberToArrayOfDigits(arr, n);
        
        System.out.println("n = " + n);
        System.out.println(Arrays.toString(arr));
    }
}



/*
run:

n = 9470
[9, 4, 7, 0]

*/

 

70+ SQL courses for beginners and professionals