What is closure and lexical scoping in JavaScript?

What is closure and lexical scoping in JavaScript?

Closure is a feature in JavaScript where an inner function has access to the outer function's variables. Lexical scoping means that the scope of a variable is determined by its location in the source code.

Can you give me an example of closure?

Sure! Here's a simple example:

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

const myInnerFunction = outerFunction();
myInnerFunction(); // Outputs: I am outside!

How does lexical scoping work in this example?

In this example, innerFunction is lexically scoped to outerFunction. It can access outerVariable because it was defined in the same scope.

What are some practical uses of closures?

Closures are often used for data encapsulation, creating private variables, and implementing function factories.