What is the difference between null and undefined in JavaScript?

Can you explain the difference between null and undefined in JavaScript?

Sure! In JavaScript, null is an intentional absence of any object value, while undefined means a variable has been declared but not assigned a value.

So, if I declare a variable but don't assign it, it will be undefined?

Exactly! For example, let x; will make x undefined. If you set x = null;, it explicitly indicates that x has no value.

Are there any situations where I should use one over the other?

Yes, use null when you want to intentionally clear a variable, and use undefined to check if a variable has been declared.

What about type checking? How do they differ?

Good question! You can use typeof to check types: typeof null returns 'object', while typeof undefined returns 'undefined'.