https://leetcode.com/problems/plus-one/

plusOne.js

var plusOne = function(digits) {
    let [carry, i] = [1, result.length-1];
    
    while(carry && i >=0){
        const n = result[i] + carry;
        carry = (n === 10) ? 1 : 0;
        digits[i--] = n % 10;
    }
    
    if(carry) digits.unshift(1);
    return digits;
};