What are closures and how do they differ from global variables?

What are closures and how do they differ from global variables?

Closures are functions that remember their lexical scope even when the function is executed outside that scope. Global variables, on the other hand, are accessible from anywhere in the code.

Can you give me an example of a closure?

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

In this example, the inner function forms a closure that retains access to the count variable.

What are the advantages of using closures?

Closures help in data encapsulation, allowing private variables, and they can also help in creating function factories and maintaining state.

Are there any downsides to using global variables?

Yes, global variables can lead to code that is harder to maintain and debug, as they can be modified from anywhere in the code, leading to potential conflicts.