Why doesn't gulp accept let?

Question

JavaScript

Hey!
I noticed that gulp doesn't run yet and throws an error if I set a variable with let.
Is there any solution?

Answer 1

use var

Answer 2

In order for uglify-js to support ES2015 + (ES6 +)
You need to install an additional experimental harmony branch

npm install --save-dev [email protected]:mishoo/UglifyJS2#harmony

You don’t need to change anything in gulpfile.js (include it), just install it and everything will work.
All settings in gulp-uglify will be set automatically.
More details uglify-js-es6