3. Values

Javascript is dynamically typed: any value produced by a calculation has a type that can be Boolean, number, character string, function or object. Variables, on the other hand, have no type and can successively contain values of different types (although this is not necessarily advisable). Javascript values are called first-class citizens because there are no restrictions on their use: they can be stored in variables, arrays, objects, passed as function arguments or returned as function results.

A distinction is made between primitive types, such as Boolean, number, string or symbol, and objects, which are basically associative tables. There are also predefined object natures (classes), for example, Date , RegExp or Error . There are also two singletons...