我的意思是在性能上有什么不同吗?哪一个能够进行最好的深度比较?有时 angular 的 equals 函数无法找到所有差异。
我还注意到,这个函数的 Angular 版本没有检查 '$$hashKey' 键。
最佳答案
通过比较值本身和所有内部属性,它们基本上表现相同。性能也接近相同,至少对于 10000 个元素,这将有 100-200 毫秒的差异。我创建了小型测试套件,警告:当您运行代码片段时,您的浏览器页面将卡住几秒钟。我不确定这种衡量性能的方法是否正确,所以请随时提出更好的方法。
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>
关于javascript - angular.equals 和 _.isEqual 有什么区别?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/39241972/