JS: Array Difference for Primitive or Object Arrays. Returns the difference. Relies on lodash.

ArrayDifference.Service.js

define(['angular', 'lodash'], function(angular, _){

	'use strict';

	angular.module('Services')
		.service('ArrayDifferenceServ', [
			function(){

				/**
				 * Compares and returns the difference between arrays based on their values.
				 * It will subtract the duplicate values from subsequent arrays from the first array.
				 * It operates similarly to array_diff in PHP, but works for arrays of objects.
				 * An optional compare function callback is allowed, make sure to prebind a context if required.
				 * This only works on the first dimension, not multidimensional arrays.
				 * @param  function compare Optional compare callback called with func(a, b), where "a" 
				 *                          is a value from the first array, and "b" is a value from
				 *                          subsequent arrays
				 * @return array            Array of values that were unique in the first array
				 */
				this.arrayDifference = function(compare){

					var arrays = Array.prototype.slice.call(arguments, 0);

					//if compare is a function, we'll use it as the callback
					//and also remove it from the arrays list to compare
					if(this.type(compare) === 'Function'){
						compare = arrays.shift();
					}else{
						compare = false;
					}

					//we're subtracting the other values off the first array, this array will therefore be modified
					//also we're cloning it to prevent affecting a potential pass by reference
					var firstArray = _.cloneDeep(arrays.shift());

					//i is the iteration of arrays
					//j is the iteration of the firstArray
					//k is the iteration of subsequent arrays values
					for(var i = 0; i < arrays.length; i++){

						//reverse iteration to prevent splicing from affecting the iterative index
						var j = firstArray.length;
						while(j--){

							var primaryValue = firstArray[j];

							for(var k = 0; k < arrays[i].length; k++){

								var secondaryValue = arrays[i][k];

								//if it is a match, we remove it from the firstArray
								if(_.isEqual(primaryValue, secondaryValue, compare)){
									firstArray.splice(j, 1);
									break;
								}

							}

						}

					}

					return firstArray;

				};

			}
		]);

});