Underscore Extension Methods Count

Allow to count values filtered by 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 count = _.count(myArray);
// count === 3

Complex usage

var min10Count = _.count(myArray, function(obj) { return obj.price >= 10; });
// min10Count === 2