reduce()

Syntax

reduce(list, expr, initial)

Applies expr for each element of the list and saves the result in _a accumulator. Consecutive calls to expr can access that value to apply more values. You also need to specify the initial value to apply for the accumulator. break can be used to terminate reduction prematurely. If a value is provided to break or continue, it will be used from now on as a new value for the accumulator.

reduce([1, 2, 3, 4], _a + _, 0); // 10
reduce([1, 2, 3, 4], _a * _, 1); // 24