How do I create block scope in JavaScript?

How do I create block scope in JavaScript?

In JavaScript, you can create block scope using the let and const keywords. Unlike var, which is function-scoped, let and const are block-scoped.

Can you give me an example of block scope?

Sure! Here's an example:

if (true) {
    let x = 10;
    const y = 20;
    console.log(x, y); // Outputs: 10 20
}
console.log(x); // ReferenceError: x is not defined

What happens if I use var instead?

If you use var, the variable will be function-scoped, meaning it will be accessible outside the block:

if (true) {
    var z = 30;
}
console.log(z); // Outputs: 30

Are there any other ways to create block scope?

Yes, you can also create block scope using IIFE (Immediately Invoked Function Expressions) or by using ES6 modules.