Can you explain lexical scope in JavaScript?

Can you explain lexical scope in JavaScript?

Sure! 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?

Of course! 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 scope.

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

If you try to access a variable from a different scope that is not in the chain of lexical scope, you'll get a reference error. For example, if innerFunction tried to access a variable defined only in another function, it wouldn't work.

Are there any exceptions to lexical scope?

In JavaScript, the main exception is when using the with statement, but it's generally discouraged. Also, closures can create situations where variables are retained beyond their original scope.