sum the all values from an array

arr.reduce((a, b) => a + b)

arrSum = function(arr){  return arr.reduce(function(a,b){    return a + b  }, 0);}

var numbers = [3, 5, 7, 2];
var sum = numbers.reduce((x, y) => x + y);
console.log(sum); // returns 17

// other way

x = sumAll(1, 123, 500, 115, 44, 88);

function sumAll() {
  var i;
  var sum = 0;
  for (i = 0; i < arguments.length; i++) {
    sum += arguments[i];
  }
  return sum;
}

//C++
int arr[5]={1,2,3,4,5};
int sum=0;
for(int i=0; i<5; i++){sum+=arr[i];}
cout<<sum;