# Types and Converting Between Them

Tell numbers, strings and booleans apart with typeof, turn text into numbers and back with Number() and String(), and know why '5' + 3 is '53' and where NaN comes from.

![Cheat sheet: Types and Converting Between Them](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/10/ed8e123e89c143cea8adc709f6c01cd6.webp)

- Category: JavaScript
- Level: Apprentice
- Tags: JavaScript, JavaScript Data Types, NaN, Primitive Value, Type Coercion, typeof Operator
- Updated: November 1, 2026

Source: https://www.ask-codey.com/cheat-sheets/javascript-types-and-converting-cheat-sheet