An immediately-invoked function expression (or IIFE, pronounced "iffy") is a JavaScript design pattern which produces a lexical scope using a JavaScript closure. This pattern has been referred to as a self-executing anonymous function.
An immediately-invoked function expression (or IIFE, pronounced "iffy") is a JavaScript design pattern which produces a lexical scope using JavaScript's function scoping.
Immediately-invoked function expressions can be used to avoid variable hoisting from within blocks, protect against polluting the global environment and simultaneously allow public access to methods while retaining privacy for variables defined within the function.
This pattern has been referred to as a self-executing anonymous function, but Ben Alman introduced the term IIFE as a more semantically accurate term for the pattern.
Immediately-invoked function expressions may be written in a number of different ways, although a common convention is to enclose both the function expression and invocation in parentheses.
(function(){
/* code */
}());
Key to understanding design patterns such as immediately-invoked function expressions is to realize JavaScript has function scope (but not block scope) and passes values by reference inside a closure.
Source:https://en.wikipedia.org/wiki/Immediately-invoked_function_expression
