what is the Immediately invoked function expression "IIFE"

as we know when we want used thing as code or than one we need a function
as this shape function name_function(param){}
when we want to be used you should call that function by used name function name_function(param)
but what if I want to use this function only one in my project then we need
IIFEs allow you to define an anonymous function and call it immediately without saving a reference. This pattern comes in handy when you want to create a scope that is shielded from the rest of a program
before we disucssion example we should know where it from come
example
"mohammedALREAI".toLocaleLowerCase() //it should be returned mohammedalrea
but if I used this shape for a number like that

``` because the number is can add a dot to add the note number  as this shape 123.20
 how can solve this problem?
 by add wrapper as this shape()
 it solves by this shape 
``` (123).toFixed() //will be return "123"
``` as it now when we are call function we call at this
``` function name (){console.log(iife)}() //it will be return this  Uncaught SyntaxError: Unexpected token ')'
``` to solve this we need wrapper which helps us to solve this problem as this shape
``` (function name (){console.log("iife")})() //return iife

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#javascript #js #node