Understanding JavaScript Closures

JavaScript closures are a fundamental concept that every developer should understand. They allow functions to access variables from an outer function even after the outer function has executed.

What is a Closure?

A closure is created when a function is defined inside another function and gains access to the outer function's variables.

function outerFunction() {
    let outerVariable = "I'm an outer variable";

    function innerFunction() {
        console.log(outerVariable);
    }

    return innerFunction;
}

const closureFunction = outerFunction();
closureFunction(); // Logs: "I'm an outer variable"

Why Use Closures?

• Data encapsulation
• Creating private variables
• Maintaining state in asynchronous operations

Closures are a powerful tool in JavaScript, enabling developers to write cleaner and more modular code.