angular.equals和_.isEqual之间有什么区别？

Question

I mean is there any difference in performance? Which one is able to make the best deep comparison? Sometimes angular's equals function is not able to find every difference.

I have also noticed, that the angular version of this function is not checking the '$$hashKey' key.

Answer 1

They basically act the same by comparing the values itself and all inner properties. Performance is also close to being the same, at least this will be a difference in 100-200 ms for 10000 elements. I have created small tests suite, warning: your browser page will freeze for few seconds when you run code snippet . I'm not totally sure is this correct way to measure performance so feel free to suggest better ways.

 angular .module("comparsion", []) .controller("ComparsionCtrl", function($scope) { var testCases = 10000; console.time("underscore"); for(var i = 0; i < testCases; i++) { var obj = createRandomObj(5, true); var obj1 = createRandomObj(5, true); _.isEqual(obj, obj1); } console.timeEnd("underscore"); console.time("angular"); for(var i = 0; i < testCases; i++) { var obj = createRandomObj(5, true); var obj1 = createRandomObj(5, true); angular.equals(obj, obj1); } console.timeEnd("angular"); // Random object generator from http://stackoverflow.com/questions/2443901/random-object-generator-in-javascript function createRandomObj(fieldCount, allowNested) { var generatedObj = {}; for(var i = 0; i < fieldCount; i++) { var generatedObjField; switch(randomInt(allowNested ? 6 : 5)) { case 0: generatedObjField = randomInt(1000); break; case 1: generatedObjField = Math.random(); break; case 2: generatedObjField = Math.random() < 0.5 ? true : false; break; case 3: generatedObjField = randomString(randomInt(4) + 4); break; case 4: generatedObjField = null; break; case 5: generatedObjField = createRandomObj(fieldCount, allowNested); break; } generatedObj[randomString(8)] = generatedObjField; } return generatedObj; } // helper functions function randomInt(rightBound) { return Math.floor(Math.random() * rightBound); } function randomString(size) { var alphaChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; var generatedString = ''; for(var i = 0; i < size; i++) { generatedString += alphaChars[randomInt(alphaChars.length)]; } return generatedString; } }); 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script> <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.min.js"></script> <div ng-app="comparsion"> <div ng-controller="ComparsionCtrl"></div> </div> 

Answer 2

angular.equals:this is angular equals comparision.

_.isEqual:this is underscore equal functionality.you need to import underscore js before using this.