Mostly a matter of preference.
The real reason for wrapping the code in an
Immediately Invoked Function Expression (IIFE) is to encapsulate variables that aren't intended to be public. It's a way to avoid creating global variables.
Code:const publicVariable = {};
;(function () {
const privateVariable = 5;
publicVariable.value = privateVariable ** 2;
})();
Now other plugins can access the public variable but not the private variable. A common purpose is when you create alias for functions, there's generally no need to expose the alias itself to the public.
Alternatively, you can create a namespace for yourself and then run everything off the namespace.
Code:const MyNamespace = {};
MyNamespace._privateVariable = 5;
MyNamespace.publicVariable = MyNamespace._privateVariable ** 2;
Javascript doesn't have private variables (
not yet...), but the underscore is used by convention to indicate that it's supposed to be private.
You can also use a namespace within an IIFE to both encapsulate variables and save some keystrokes.
Code:const MyNamespace = {};
;(function ($) {
const privateVariable = 5;
$.value = privateVariable ** 2;
})(MyNamespace);
Nowadays, all of this is considered "old school" ways of handling variable scope. Web development these days use modules with import/export statements to manage this, however, I don't think the module implementation will be supported by the MV engine or adopted by plugin writers any time soon.