What you'll learn in this JavaScript data types tutorial

This interactive JavaScript tutorial has 10 hands-on exercises. Estimated time: 20 minutes.

1. The seven primitive types — JavaScript has seven primitive types. You have already seen a few — now let's meet them all.
2. number — JavaScript does floats by default — JavaScript uses a 64-bit float for ALL numbers — integers and decimals share one type.
3. string — text in JavaScript — Strings can use single quotes, double quotes, or backticks. Backtick strings (template literals) are the most powerful —…
4. boolean — just two values — `true` and `false`. That's it. They control every `if` statement, every loop condition, every decision.
5. null vs undefined — two 'nothing' values — JavaScript has two ways to say 'no value here', which confuses everyone:
6. The coercion trap — == vs === — This is one of JavaScript's most famous footguns. `==` (loose equality) converts types before comparing — `===` (strict …
7. Type conversion — be explicit — Rather than letting JS coerce types silently, convert explicitly:
8. Truthy and falsy — JavaScript treats certain values as `false` in boolean contexts:
9. NaN — the weird number — `NaN` means 'Not a Number' — but `typeof NaN === 'number'`. It is JavaScript's way of saying 'I tried to do math but the…
10. All types in one program — Final challenge — no starter code.

JavaScript Data Types concepts covered

• Everything has a type