What is scope chaining in JavaScript?

What is scope chaining in JavaScript?

Scope chaining in JavaScript refers to the way nested functions can access variables from their parent scopes.

Can you give me an example of scope chaining?

Sure! Here's a simple example:

function outerFunction() {
    let outerVar = 'I am from outer scope';
    function innerFunction() {
        console.log(outerVar);
    }
    innerFunction();
}
outerFunction();

In this example, innerFunction can access outerVar due to scope chaining.

What happens if I try to access a variable from a non-parent scope?

If you try to access a variable from a non-parent scope, JavaScript will throw a ReferenceError, as it cannot find the variable.

Are there any real-world applications of scope chaining?

Yes, scope chaining is essential in closures, event handlers, and callback functions, allowing for encapsulation and data privacy.