Why Practical closure use cases in Javascript? - Purpose & Use Cases

The Big Idea

Discover how closures can quietly keep your data safe and your code neat without extra fuss!

The Scenario

Imagine you want to keep track of how many times a button is clicked on a webpage. Without closures, you might try to use global variables or pass counters around everywhere manually.

The Problem

Using global variables or passing counters manually is error-prone and messy. It's easy to accidentally reset the count or lose track of it, especially when your code grows bigger or you have many buttons.

The Solution

Closures let you create a private space to store data like the click count. This way, the count stays safe and updates only when you want, without cluttering the global space or risking accidental changes.

Before vs After

✗ Before

let count = 0;
function click() {
  count++;
  console.log(count);
}

✓ After

function makeCounter() {
  let count = 0;
  return function() {
    count++;
    console.log(count);
  };
}
const click = makeCounter();

What It Enables

Closures enable you to create functions with private data that remembers state between calls, making your code cleaner and safer.

Real Life Example

When building a web app, closures help you create counters, timers, or settings that remember user choices without exposing them globally or mixing them up.

Key Takeaways

Closures keep data private and safe inside functions.

They help track state like counters or settings easily.

Using closures makes your code cleaner and less error-prone.