javascript var语句和性能

本文介绍了javascript var语句和性能的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

选项1：无分配的多个变种

function MyFunction() { var a = null; var b = null; .... var z = null; a = SomeValue; b = SomeValue2; .... }

选项2：一个var声明，没有作业

function MyFunction() { var a, b ..., z; a = SomeValue; b = SomeValue2; .... }

选项3：多个var分配的陈述

function MyFunction() { var a = SomeValue; var b = SomeValue2; .... var z = SomeValue26; }

使用特定选项是否有任何性能优势？对于原始类型分配 AND 对象引用分配是否属实？

Is there any performance benefit of using a particular option? Is it true for both primitive type assignments AND object reference assignments?

谢谢您的输入。

推荐答案

过早优化是所有邪恶的根源

我认为任何此类期权都不会有任何重大性能变化。 （IMO）第三个选项是最易读的选项，最接近动态内存分配，如 C＃ etc'。但这是我的拙见，选择你最喜欢的。

I don't think there will be any significant performance change with any of this options. (IMO) The third option is the most readable option and closest to dynamic memory allocation like C# etc'. But this is my humble opinion, Choose what you like the most.

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If it really bothers you and you can't sleep without an answer, test it with jsPerf.

@Chad制作了一个 jsPerf ，这样你就可以今晚睡得好......

@Chad made a jsPerf so you can sleep well tonight...