What are closures and how do they compare to other programming patterns?

What are closures in programming?

Closures are functions that retain access to their lexical scope, even when the function is executed outside that scope.

How do closures differ from other patterns like callbacks?

Closures can maintain state between function calls, while callbacks are typically stateless and rely on external variables.

Can you give an example of a closure in JavaScript?

Sure! Here's a simple example:

function makeCounter() {
    let count = 0;
    return function() {
        count++;
        return count;
    };
}
const counter = makeCounter();
console.log(counter()); // 1
console.log(counter()); // 2

This function creates a counter that retains its state.

What are some other programming patterns I should know about?

Some important patterns include callbacks, promises, async/await, and the module pattern. Each has its own use cases.