JS data type

Data types are divided into basic data types and reference data types raw data types or basic data types

Small data to store

1.null empty, does not exist;

2.underfined declaration not assigned, function does not return a value

3.number number, decimal, Integer, NAN

4.boolean Judgment True,flase

5.string string, single or double quotation mark representation

6.symbol generates a unique value ES6 new

Reference data type

Big Data for storage

The 1.object object object is an unordered set of properties, where the "property" can be a base value, an object or a function

2.Array arrays

3.function function

object是所有引用类型父级

Detection data type

typeof

JS data type