Greasy Fork

When I was trying to use !function It gave me false, Is there a way to use it?

To use what? If you don't know basics of the language you need to learn it here: https://javascript.info/ , not on the website for ready scripts.

!function in javascript is equal nothing, this doesn't exist

! means not...

function FunctionName() //Creates a variable named FunctionName
{ //Starts the function
var VariableName = true; //Creates a new variable with the value of true

if (VariableName !== false) //Check if the variable VariableName is NOT equal false
{ //Starts the function
alert('yes the variable VariableName is NOT equal true'); //If the variable VariableName is NOT equal false show a message
} //Finishes the if condition

} //Finishes the function

FunctionName(); //Executes the function....

btw this doesn't do anything does it? https://greasyfork.org/en/scripts/421266-easy-cookie-manager

Please delete that script or make it unlisted...

@hacker09, it's a library so it's intended to be used by other scripts. Don't make hasty judgments.

@Jonas12, what you saw is a well-known method to make IIFE, see https://flaviocopes.com/javascript-iife/

@wOxxOm

Ok.
He just showed 3 weird function syntaxes using unary operators, but didn't explain why they are weird and what makes them better or worse than arrow functions

"Weird" because there's no reason to use those unary operators but some people may still want to just for fun or to make the minified output shorted by a few characters. Also, IIFE is not better or worse than an arrow function because it's not an alternative: you can use them together e.g. (() => { ....... })()

er, "shorted" -> "shorter"

@Konf Said

To use what? If you don't know basics of the language you need to learn it here: https://javascript.info/ , not on the website for ready scripts.

Did you see the title?