Lets look at a simple example. This is a simplest form of a Closure. In JavaScript variables define in outside of the function are automatically available inside. Because in JavaScript its using ...

In JavaScript, the function object itself contains a non-accessible property ... Since function expressions may be declared, their declaration should form a closure based upon the declaring ...

Note that these closures follow the Module Design Pattern. Those three public functions form closures that share the same lexical environment. Thanks to JavaScript's lexical scoping, they each have ...