What is a self-invoking function?

An Immediately Invoked Function Expression (IIFE) is a function that is defined and executed immediately after its creation.

It has the following structure:

1. The function is declared inside parentheses ().
2. Immediately after the declaration, another set of parentheses () follows to invoke this function.

(function() {
  // Code inside the function
})();

Main advantages of using IIFE:

• Scope isolation: All variables declared inside the IIFE are local to that function and do not pollute the global namespace.
• Creating private variables and functions: Thanks to scope isolation, private members can be created.
• Executing code immediately after definition: Useful for initialization or one-time code execution.

Example of IIFE with arguments:

(function(message) {
  console.log(message); // Will output "Hello!"
})("Hello!");