sum(elementSelector = identityFunction)

Returns the sum of selected values.

Arguments

• elementSelector (function): function that must return the value to make the sum, taking each element.

Returns

(Number): sum of the elements.

Example

Enumerable
        .from(1, 2, 3)
        .sum();
// 6

const people = [
  { username: 'Matteo', age: 19 },
  { username: 'foo', age: 8 },
  { username: 'bar', age: 27 },
];

Enumerable
        .from(people)
        .sum(x => x.age);
// 54