JavaScript study notes (12) simple data types and complex data types

1. Concept

Simple data types: also known as basic data types, value types

                                 如string、number、boolean、undefined、null

                                *Simple data type null, returns an empty object object

Complex data types: also known as reference types

                                Objects created by new (system objects, custom objects), such as Object, Array, Date, etc.

2. Memory allocation:

Simple data type, stored in the stack, which directly opens up a space to store values

Complex data types, first store the address in the stack, expressed in hexadecimal, and then this address points to the data in the heap