In JavaScript, bytes are not a basic data type. The basic data types in JavaScript include: String, Number, Boolean, Symbol and null.
However, in some cases, we may need to deal with byte data, and usually numeric types can be used to represent bytes. For example, a byte can be represented as an integer between 0 and 255, because a byte can represent 2^8 different values, or 256 different values.
When processing byte data, we usually use numeric types to represent the value range of bytes, rather than treating bytes as independent basic data types. There is no special "byte" type in JavaScript, but byte data can be simulated through numeric types.