What is lexical scope in JavaScript?

What is lexical scope in JavaScript?

Lexical scope refers to the visibility of variables in nested functions. It means that a function can access variables from its own scope and from the outer scopes where it was defined.

Can you give me an example of lexical scope?

Sure! Here's a simple example:

function outerFunction() {
    let outerVariable = 'I am outside!';
    function innerFunction() {
        console.log(outerVariable);
    }
    innerFunction();
}
outerFunction();

In this case, innerFunction can access outerVariable because of lexical scoping.

What happens if I try to access a variable from a different scope?

If you try to access a variable that is not in the current scope or any of its outer scopes, you'll get a ReferenceError. For example, if innerFunction tried to access a variable defined only in another function, it wouldn't work.

How does lexical scope differ from dynamic scope?

Lexical scope is determined at compile time based on the location of the function definition, while dynamic scope is determined at runtime based on the call stack. JavaScript uses lexical scoping.