𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗗𝗮𝘁𝗮 𝗧𝘆𝗽𝗲𝘀: 𝗣𝗿𝗶𝗺𝗶𝘁𝗶𝘃𝗲 𝘃𝘀 𝗡𝗼𝗻-𝗣𝗿𝗶𝗺𝗶𝘁𝗶𝘃𝗲
Data types define the value a variable holds. You need this knowledge to write clean code.
JavaScript uses two main categories.
Primitive Data Types These store one simple value. They are immutable.
- String: Text
- Number: Numbers
- Boolean: True or false
- Undefined: No assigned value
- Null: Intentional empty value
- Symbol: Unique IDs
- BigInt: Huge numbers
Non-Primitive Data Types These store complex data. They are mutable.
- Array: Lists of values
- Object: Key-value pairs
- Function: Reusable code
Comparison rules:
Primitives compare by value. Two variables with the number 10 are equal.
Non-primitives compare by reference. Two objects with the same data are not equal. They occupy different memory spots.
Pick the right type to stop bugs.