Grasping Closures in JavaScript: Practical Use Cases & Examples

Dive into closures, learn their importance, and master implementing them in real-life coding situations

Photo by Kilian Seiler on Unsplash

JavaScript closures have been around for quite some time now, yet many programmers still struggle to fully comprehend how they work and why they matter. Simply put, closures enable data privacy, reduce global namespace pollution, and facilitate modular design patterns.

Let’s dive deeper into closures, explore their significance, and examine practical implementation strategies through engaging examples.

What Are Closures?

At their core, closures are nested functions that access variables from outer parent scopes even after those outer functions have returned. The closure preserves the environment in which it was created, allowing inner functions to retain access to external variables long after execution has completed.

Here’s an illustrative example:

function createCounter() {
  let count = 0;
  
  return function incrementCounter() {
    count++;
    console.log(`Count value is ${count}`);
  };
}

const counter = createCounter();
counter(); // Count value is 1
counter(); // Count value is 2