IIFE (Immediately Invoked Function Expression)

You can make variables inside one IIFE accessible to another IIFE by returning the variables and assigning them to a shared scope variable. While IIFEs do create their own isolated scope, they can communicate with the outer scope by returning values or by modifying variables that both IIFEs can access. A common pattern is to have both IIFEs assign their public interfaces to properties of the same object, creating a namespace. For example: ```javascript var namespace = {}; // First IIFE adds to namespace (function() { var privateVar = 'private'; namespace.method1 = function() { return privateVar; }; })(); // Second IIFE can use what first one exposed (function() { namespace.method2 = function() { return namespace.method1() + ' accessed'; }; })(); ``` This is one way modules were implemented before ES6 modules.