Null and Undefined

👨‍💼 Great job! You've learned about JavaScript's two "empty" values.

🦉 Key takeaways:

undefined is JavaScript's default for "no value assigned"
null is what you use when you want to explicitly say "no value"
typeof undefined is "undefined"
typeof null is "object" (a famous JavaScript quirk!)
null == undefined is true (loose equality)
null === undefined is false (strict equality)

Always use === (strict equality) in your comparisons! Loose equality (==) has surprising behaviors that can cause bugs.

In practice, you'll see undefined more often - it's what you get when accessing a property that doesn't exist or a function parameter that wasn't passed. You'll use null when you want to explicitly clear a value or indicate "nothing here on purpose."

01. Hello JavaScript/04. Null and Undefined (🏁 solution)

Null and Undefined