Object.defineProperty() 和 Object.defineProperties() 之间的性能差异

Question

我正在寻找这两种方法之间的主要区别。

一些网站提到了可读性问题，但我的担忧主要与性能有关。似乎 defineProperty() 更快，但我找不到原因。

var FOR_TIME = 10000;


console.time("prop");
for(var i = 0; i < FOR_TIME; i++) {
    var test = {};
    Object.defineProperty(test, "ba", {});
    Object.defineProperty(test, "bab", {});
    Object.defineProperty(test, "bac", {});
}
console.timeEnd("prop");

console.time("props");
for(var i = 0; i < FOR_TIME; i++) {
    var test = {};
    Object.defineProperties(test, {
        a: {},
        ab: {},
        ac: {}
    })
}
console.timeEnd("props");

控制台结果如下：（执行3次）

1- prop: 9.251ms props: 17.034ms
2- prop: 10.050ms props: 22.443ms
3- prop: 11.013ms props: 17.086ms

使用的节点版本：v10.15.0

Answer 1

您可以将基准阅读为："Oh, defineProperty is more than two times faster"。

或者您可以将其读作："Even defineProperties only takes 20ms for 10.000 iterations, which means that it will rarely cause any problems at all, unless you are creating millions of instances in a loop that runs thousand of times."

Object.defineProperty() 和 Object.defineProperties() 之间的性能差异

Performance difference between Object.defineProperty() and Object.defineProperties()

javascript

ecmascript-5

defineproperty