Question

Gets the sum of the numeric values in the sequence.

Signature

Sequence.sum = function(valueFn) { /*...*/ }

Sequence.sum = function sum(valueFn) {
  if (typeof valueFn !== "undefined") {
return this.sumBy(valueFn);
  }

  return this.reduce(function(x, y) { return x + y; }, 0);
}

Name	Type(s)	Description
valueFn	Function?	The function used to select the numeric values that will be summed up.
returns	*	The sum.

Examples

Lazy([]).sum()                     // => 0
Lazy([1, 2, 3, 4]).sum()           // => 10
Lazy([1.2, 3.4]).sum(Math.floor)   // => 4
Lazy(['foo', 'bar']).sum('length') // => 6