Explain IIFE (Immediately Invoked Function Expression).

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

It looks like this:

(function () {
    console.log("This is an IIFE!");
})();

🔹 Breakdown:

1. Function Expression
   • (function() { ... }) → The function is wrapped inside parentheses so that JavaScript treats it as an expression (not a declaration).
2. Immediate Invocation
   • () right after the function tells the engine to execute it immediately.

🔹 Why use IIFE?

Avoid polluting the global scope
Variables inside an IIFE are private and cannot be accessed outside.

(function () { 
var privateVar = "I am private"; 
console.log(privateVar); // ✅ Accessible here 
})(); 
// console.log(privateVar); // ❌ Error: privateVar is not defined

Create private scope (especially useful before let and const were introduced in ES6).

Run code immediately without explicitly calling a function later.

🔹 Variations

Named IIFE (function myFunc() { console.log("Named IIFE"); })();

Arrow Function IIFE (() => { console.log("IIFE with arrow function"); })();

With Parameters ((name) => { console.log("Hello " + name); })("Himanshu");

✅ In short:
An IIFE is a function expression that executes immediately after being created, mainly used for data privacy and avoiding global namespace pollution.