Immediately Invoked Function Expression or IIFE is a self-executing javascript anonymous function. This function runs as soon as it is declared rather than waiting for being invoked after declaration. AN IIFE has two parts:

• 1. An anonymous function declaration is enclosed in a grouping operator ()
• 2. A () immediately after the declaration to call the function.

1//An IIFE
2(function greet()
3{
4    console.log("Hello World");
5})();
6 
7//OUTPUT: Hello World