adding numbers within an array code example

Example 1: adding numbers in an array javascript

console.log(
  [].reduce((a, b) => a + b)
)

Example 2: Add One To Number in array

vector<int> Solution::plusOne(vector<int> &a) {    int n=a[a.size()-1]+1;    vector<int> r;    r.push_back(n%10);    int carry=n/10;    if(carry==0)    {        a[a.size()-1]++;        return a;    }    for(int i=a.size()-2; i>=0; i--)    {        n=a[i]+carry;        carry=n/10;        r.push_back(n%10);    }    reverse(r.begin(),r.end());    return r;}XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX