javascript--variable

This article briefly describes the data types of JavaScript variables, as well as variable type detection and type conversion

First, Introduction

There are 6 types of data for JavaScript variables, including 5 primitive types and 1 object types. I prefer to use logical graphs to summarize the knowledge points, so more clear, the figure is as follows:

Second, note: 1, variable assignment

Reference type: As long as no new is allocated memory space, so when you copy the value of a variable in an assignment, a pointer to the object is copied, and two variables refer to the same object

2. Function Transfer parameter

The parameter passing of a JavaScript function is passed by value , except that the value of the reference type is a pointer, so the change reacts to the outside of the function.

javascript--variable