What is JavaScript

First, what is JavaScript?

JavaScript is a page that transforms static Web pages into dynamic pages that enable users to interact and respond to events.

Knowledge Expansion:

HTML is the page structure, CSS is the page style, JavaScript is the page dynamic.

Second, variable and constant

What is a variable? A variable is one that can be changed in the course of a run, a constant instead.

Third, the data type

JavaScript data types are primarily, String, Boolean, numeric, and special data type "escape characters"

String, Boolean, null, undefined, number

What is JavaScript