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

Question

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.

Answer 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
}

Answer 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.

Answer 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.

1. User Settings

2. JSHint config

3. "jshint.config": {} (Edit)

4. 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

Answer 4

If you're using VSCode:

1.

• 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.

---

2.

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.

Answer 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 */.

Answer 6

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