const与var在node . js中“需要”模块时是否存在效率差异

I was reading the documentation for https://github.com/rvagg/bl and I noticed that, in the examples, they use const to require a module and this made me wonder: is this a good practice? I mean, to me, this looked as a good idea.

我正在阅读https://github.com/rvagg/bl的文档，我注意到，在示例中，他们使用const来要求一个模块，这让我想知道:这是一个好的实践吗?对我来说，这是个好主意。

A direct example from the link above is:

上面链接的一个直接例子是:

const BufferList = require('bl')

var bl = new BufferList()
bl.append(new Buffer('abcd'))
bl.append(new Buffer('efg'))
/*...*/

I also noticed the lack the semicolons in the example but well, that has been discussed elsewhere thoroughly.

我还注意到示例中缺少分号，但是其他地方已经详细讨论过了。

1 个解决方案

#1

The const makes perfect sense here:

这里的const完全说得通:

It documents that the ~~object~~ reference is not going to change.
它记录对象引用不会改变。
It has block scope (same as let) which also makes sense.
它具有块范围(与let相同)，这也有意义。

Other than that it comes down to personal preference (using var, let or const)

除此之外，它还取决于个人偏好(使用var, let或const)

#1