Underscore Extension Methods Average

Allow to create average by passing collection values using given iterator.

Usage

Introduction

var myArray = [
    { productId: 1, title: 'My Product 1', price: 10, quantity: 1 },
    { productId: 2, title: 'My Product 2', price: 15.5, quantity: 4 },
    { productId: 3, title: 'My Product 3', price: 7.25, quantity: 1 }
];

Simple usage

var averageQuantity = _.average(myArray, function(obj) { return obj.quantity; });
// averageQuantity  === 2

Complex usage

var averageByProduct = _.average(myArray, function(obj) { return obj.price * obj.quantity; });
// averageByProduct === 13.21 ...