What is the meaning of “$$$1” sign in Bootstrap.js file

Question

In the following JavaScript code there is a dollar sign “$$$1". What does it mean?

 var Util = function ($$$1) {...} //Line 62 bootstrap.js V4 $$$1(this).one(Util.TRANSITION_END, function () { called = true; }); //Line 103 bootstrap.js V4 

Answer 1

It is a reference to jQuery. If you see the definition of the function, it is something like this:

var Util = function ($$$1) {...}($);

Notice the $ at the end. It means that the function expression is being called with a variable $ , which refers to jQuery. Then throughout the function, jQuery is referred to as $$$1 . So, a call like this:

$$$1(this).one(Util.TRANSITION_END ...

becomes like this:

$(this).one(Util.TRANSITION_END ...

which is a regular jQuery event binding.

Answer 2

It's just another variable name, though a pretty opaque one, since it's not descriptive at all. If you search-replaced all $$$1 with someFunc , the script would still work just as well.