JavaScript on timerring

Introduction to Web APIs

Sat, 10 Jul 2021 21:28:31 +0800

Strictly speaking, most of what we learned in the JavaScript section belongs to ECMAScript. ECMAScript, or ES, defines language standards such as the syntax rules for variables, data types, expressions, statements, and functions. Browsers implement most of the ECMAScript specification and extend it with practical features. These extensions are called Web APIs.

JavaScript Data Types

Fri, 09 Jul 2021 23:01:26 +0800

JavaScript is a weakly typed, or dynamic, language. You do not need to declare a variable’s type in advance; its type is determined automatically while the program runs.

var age = 10; // Number
var areYouOk = 'yes'; // String

JavaScript has dynamic types, meaning the same variable can be used for different types (its type can change).

var x = 6; // x is a number
var x = "Bill"; // x is a string

JavaScript Objects

Fri, 09 Jul 2021 20:00:00 +0800

Objects are a JavaScript data type. We have already learned about numbers, strings, booleans, and undefined. An object can be understood as a collection of data. It consists of properties and methods.

JavaScript Functions

Fri, 09 Jul 2021 16:58:16 +0800

Declaration (Definition) #

Declaring (defining) a complete function involves five parts: the keyword, function name, formal parameters, function body, and return value.

JavaScript Arrays

Fri, 09 Jul 2021 16:00:00 +0800

Arrays: An array is a data type that stores data in order.

JavaScript Operators and Control Flow

Fri, 09 Jul 2021 15:07:15 +0800

Commonly used operators in JavaScript include:

Arithmetic operators
Increment and decrement operators
Comparison operators
Logical operators
Assignment operators

JavaScript Fundamentals

Wed, 07 Jul 2021 16:30:35 +0800

Brendan Eich (born 1961) completed the design of JavaScript in 10 days.

It was originally named LiveScript and was later renamed JavaScript after a collaboration with Sun.
JavaScript is one of the world’s most popular languages. It is a scripting language that runs on the client side (“script” means a script), and now it can also be used for server-side programming with Node. Js technology.
Scripting language: it does not need to be compiled; during execution, the js interpreter (js engine) interprets and executes it line by line.