Javascript Journey: Master Closures & Scopes - JavaScript Closures Mastery

Example

function outerFunction() { let outerVar = 'I am outside!'; function innerFunction() { console.log(outerVar); } return innerFunction; } let inner = outerFunction(); inner();

Scenario

This demonstrates a basic closure, where `innerFunction` accesses `outerVar`, a variable in its lexical scope, even after `outerFunction` has executed.

Example

function createCounter() { let count = 0; return { increment: function() { count += 1; return count; }, decrement: function() { count -= 1; return count; } }; } let counter = createCounter();

Scenario

Showcases how closures can be used to encapsulate and manage private data, allowing direct interaction only through defined methods.

Example

function asyncDataLoader(url) { return fetch(url) .then(response => response.json()) .then(data => console.log('Data loaded:', data)); } asyncDataLoader('https://api.example.com/data');

Scenario

Illustrates how closures facilitate asynchronous programming, allowing callbacks to access the scope in which they were created, thereby managing state across asynchronous operations.