Why does JSHint throw a warning if I am using const?

问题

This is the error I get when using const:

<error line="2" column="1" severity="warning" message="&apos;const&apos; is available in ES6 (use esnext option) or Mozilla JS extensions (use moz)." source="jshint.W104" />

My code looks like this:

const Suites = {
    Spade: 1,
    Heart: 2,
    Diamond: 3,
    Club: 4
};

The code works fine only JSHint is warning me every time.

回答1:

When relying upon ECMAScript 6 features such as const, you should set this option so JSHint doesn't raise unnecessary warnings.

~~/*jshint esnext: true */~~ (Edit 2015.12.29: updated syntax to reflect @Olga's comments)

/*jshint esversion: 6 */

const Suites = {
    Spade: 1,
    Heart: 2,
    Diamond: 3,
    Club: 4
};

This option, as the name suggests, tells JSHint that your code uses ECMAScript 6 specific syntax. http://jshint.com/docs/options/#esversion

Edit 2017.06.11: added another option based on this answer.

While inline configuration works well for an individual file, you can also enable this setting for the entire project by creating a .jshintrc file in your project's root and adding it there.

{
  "esversion": 6
}

回答2:

You can add a file named .jshintrc in your app's root with the following content to apply this setting for the whole solution:

{
    "esversion": 6
}

James' answer suggests that you can add a comment /*jshint esversion: 6 */ for each file, but it is more work than necessary if you need to control many files.

回答3:

I got this same warning when using an export statement. I'm using VS Code and used a similar approach to Wenlong Jiang's solution.

User Settings
JSHint config
"jshint.options": {} (Edit)
Use double quotes when specifying "esversion"

Or copy this snippet into User Settings:
```
"jshint.options": {
  "esversion": 6,
}
```

Creating a .jshintrc file isn't necessary if you want to configure the global jshint settings for your editor

回答4:

If you're using VSCode:

Go to preferences -> settings (cmd + ,)
Type jshint.options into the search bar
Hover over it and click on the pencil icon
Its now appended on the right side.
Add "esversion": 6 to the options object.

Or simply add this to your user settings:

"jshint.options": {
    "esversion": 6
}

[UPDATE] new vscode settings

Go to preferences -> settings (cmd + ,)
type jshint into search

continue with step 2.

回答5:

I spent ages trying to fix this. Every solution talks about 'setting options'. I don't know what that means. Finally, I figured it out. You can just include a commented out line at the top of the file /*jshint esversion: 6 */.

回答6:

You can specify esversion:6 inside jshint options object. Please see the image. I am using grunt-contrib-jshint plugin.

回答7:

When you start using ECMAScript 6 this error thrown by your IDE.

There are two options available:

if you have only one file and want to use the es6 then simply add below line at the top of the file.

/*jshint esversion: 6 */

Or if you have number of js file or you are using any framework(like nodejs express)you can create a new file named .jshintrc in your root directory and add code below in the file:

{
    "esversion": 6
}

If you want to use the es6 version onward for each project you can configure your IDE.

回答8:

If you are using Webstorm and if you don't have your own config file, then just enable EcmaScript.next in Relaxing options in in

Settings | Languages & Frameworks | JavaScript | Code Quality Tools | JSHint

See this question How-do-I-resolve-these-JSHint-ES6-errors

回答9:

If you are using Grunt configuration, You need to do the following steps

Warning message in Jshint:

Solution:

Set the jshint options and map the .jshintrc.js file

Create the .jshintrc.js file in that file add the following code

{  
  "esversion": 6  
}

After configured this, Run again It will skip the warning,

回答10:

Create a file called, say jshint_opts with this content: { "esversion": 6 }

Then invoke jshint with something like this command line:

jshint --config jshint_opts lib/*.js

回答11:

In your package.json you can tell Jshint to use es6 like this

"jshintConfig":{
    "esversion": 6 
}

回答12:

If using Sublime Text 3:

Go to Preferences -> Settings
Under Preferences.sublime-settings—User add "esversion": 6

来源：https://stackoverflow.com/questions/27441803/why-does-jshint-throw-a-warning-if-i-am-using-const

标签

javascript

node.js

const

jslint

jshint