1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | 18x 4x 4x 4x 15x 15x 4x 3x 1x | import Iterator from '../iterators/Iterator'; Iterator.prototype.average = function average() { let sum = 0; let count = 0; for (let item of this) { sum += item; count++; } if (count > 0) { return sum / count; } return NaN; }; |