Both represent “no value”—but they are not the same.

🔹 null: Intentionally Empty

You use it when you want to say “this has no value.”

let user = null; // No user is logged in

Think: An empty box you purposely left empty.

🔸 undefined: Value Not Set

JS uses this automatically when a variable is declared but not initialized.

let name;
console.log(name); // undefined

Think: A box you forgot to put something in.

🔍 When to Use What

Use null Use undefined
To show intentional emptiness When a variable is uninitialized
Example: user = null Example: let score; (no assignment)

✅ Key Takeaway

  • Use null when you choose to say “no value”
  • undefined is JavaScript’s default for “not yet set”

🧪 Quiz Time

Q1: What does undefined represent? A) A variable that has been declared but not assigned a value B) A deliberate absence of a value C) A syntax error D) A type of object

Q2: Which is true about null and undefined? A) null === undefined B) typeof null returns "undefined" C) null is used for intentional absence D) undefined is used when assigning null

<
Previous Post
🎮 Why You Should Be Using HTML canvas in Your Projects
>
Next Post
🖼️ Canvas vs. SVG: What’s the Difference?