WebStorm “当前 JavaScript 版本不支持 Let 定义”
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/39054143/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
WebStorm “Let definition are not supported by current JavaScript version”
提问by AST
I am trying to use new tools available for coding in JavaScript. I've seen the post PhpStorm "Let definition are not supported by current JavaScript version". I've tried as suggested over there, but do not work.
我正在尝试使用可用于 JavaScript 编码的新工具。我看过PhpStorm的帖子“当前的 JavaScript 版本不支持让定义”。我已经按照那边的建议尝试过，但不起作用。
When I hover over the export
当我悬停在 export
Export declarations are not supported by current JavaScript version
当前 JavaScript 版本不支持导出声明
When I hover over the yield
当我悬停在 yield
Generators are not supported by current JavaScript version
当前 JavaScript 版本不支持生成器
and hovering over the let
并悬停在 let
Let definition are not supported by current JavaScript version
当前 JavaScript 版本不支持 Let 定义
So the question is how to upgrade the JavaScript version?
那么问题来了，如何升级 JavaScript 版本呢？
回答by YanMeng
It can be set up like in the following image:
可以如下图所示进行设置：
Flow:File -> Settings -> Languages & Frameworks -> Javascript
流程：文件 -> 设置 -> 语言和框架 -> Javascript
回答by newFinancier
Make sure you restart your IDE after changing the JS language version to ECMAScript 6.
将 JS 语言版本更改为 ECMAScript 6 后，请确保重新启动 IDE。
回答by Glen Pierce
You need to set your JavaScript version in the IDE. This can be accessed on Windows with ctrl + alt + s. You need at least ECMA Script 6 to use let.
您需要在 IDE 中设置 JavaScript 版本。这可以在 Windows 上使用 ctrl + alt + s 访问。您至少需要 ECMA Script 6 才能使用let.
回答by Serpearl
As others suggested, setting the language version does fix this:
正如其他人所建议的，设置语言版本确实可以解决这个问题：
File -> Settings -> Languages & Frameworks -> Javascript
File -> Settings -> Languages & Frameworks -> Javascript
However, that was not enough in my case. If you're experiencing these errors in a project that is nested within another project you must apply the JS language settings to the parent projectas well.
然而，这对我来说还不够。如果您在嵌套在另一个项目中的项目中遇到这些错误，您还必须将 JS 语言设置应用于父项目。
In my case, it was a client-side React app nested inside a larger Java-based web-portal (Working with IntelliJ IDEA Ultimate, which uses the same settings flow). I am adding this answer to the discussion in the hope that it can help someone in the future.
就我而言，它是一个嵌套在基于 Java 的更大网络门户中的客户端 React 应用程序（使用 IntelliJ IDEA Ultimate，它使用相同的设置流程）。我将此答案添加到讨论中，希望它可以在将来对某人有所帮助。
回答by VIKAS KOHLI
You have to change the settings for using this keyword
您必须更改使用此关键字的设置
Go to File -> Settings -> Languages & Frameworks -> Javascript (Select ECMA Script 6)
转到文件 -> 设置 -> 语言和框架 -> Javascript（选择 ECMA Script 6）
