What is scope and shadowing in programming?

What is scope and shadowing in programming?

Scope refers to the visibility of variables in different parts of your code, while shadowing occurs when a variable in a local scope has the same name as a variable in an outer scope.

Can you give me an example of scope in JavaScript?

Sure! In JavaScript, a variable declared inside a function is not accessible outside of that function. For example:

function myFunction() {
    let x = 10; // x is in the local scope
}
console.log(x); // This will throw an error because x is not defined here.

What about shadowing? How does it work?

Shadowing happens when a variable in a local scope has the same name as a variable in an outer scope. For example:

let x = 5;
function myFunction() {
    let x = 10; // This x shadows the outer x
    console.log(x); // Outputs 10
}
myFunction();
console.log(x); // Outputs 5

Are there any best practices to avoid issues with scope and shadowing?

Yes! It's best to use unique variable names, especially in nested functions, and to understand the scope chain to avoid confusion.