Home Web Front-end JS Tutorial JavaScript tutorial: Getting to know JavaScript for the first time

JavaScript tutorial: Getting to know JavaScript for the first time

Dec 22, 2016 pm 03:52 PM

What is JavaScript?

JavaScript is an object- and event-driven scripting language with security features. The purpose of using it is to realize linking multiple objects in a Web page together with HTML hypertext markup language and Java script language (Java applet) to interact with Web clients. This allows you to develop client applications, etc. It is implemented in the standard HTML language by embedding or calling in. Its appearance makes up for the shortcomings of the HTML language. It is a compromise between Java and HTML and has the following basic features:

Scripting language

JavaScript is a scripting language that uses small program segments to implement programming. Like other scripting languages, JavaScript is an interpreted language, which provides an easy development process.

Its basic structural form is very similar to C, C++, VB, and Delphi. But it does not need to be compiled first like these languages, but is interpreted line by line during the running of the program. It is combined with HTML markup to make it easier for users to use.

Object-based language

JavaScript is an object-based language and can be regarded as an object-oriented language. This means that it can use objects it has already created. Therefore, much functionality can come from the interaction of methods of objects in a scripting environment with scripts.

Simplicity

The simplicity of JavaScript is mainly reflected in: First of all, it is a simple and compact design based on Java's basic statements and control flow, which is a very good transition for learning Java. Secondly, its variable type is weakly typed and does not use strict data types.

Security

JavaScript is a security language. It does not allow access to the local hard drive, cannot store data on the server, does not allow modification and deletion of network documents, and can only browse information through a browser. or dynamic interaction. This effectively prevents data loss.

Dynamics

JavaScript is dynamic, it can respond directly to user or customer input without going through the Web service program. It responds to users in an event-driven manner. The so-called event-driven refers to the action generated by performing a certain operation on the home page, which is called an "event". For example, pressing the mouse, moving the window, selecting the menu, etc. can be regarded as events. When an event occurs, a corresponding event response may be triggered.

Cross-platformability

JavaScript depends on the browser itself and has nothing to do with the operating environment. As long as the computer can run the browser and the browser supports JavaScript, it can be executed correctly. Thus realizing the dream of "write once and travel all over the world".

In fact, the most outstanding thing about JavaScript is that it can do a lot of things with a small program. There is no need for a high-performance computer. The software only requires a word processing software and a browser. There is no need for a WEB server channel. Everything can be done through your own computer.

In summary, JavaScript is a new description language that can be clamped into HTML files. The JavaScript language can respond to user demand events (such as form input) without using any network to transmit data back and forth. Therefore, when a user inputs a piece of data, it does not need to be passed to the server. ) processing and then passing it back, which can be directly processed by the client application.


Writing the first JavaScript program

Below we use an example to write the first JavaScript program. It explains how JavaScript scripts are embedded into HTML documents.

For example:

<html>
<head>
<meta charset="utf-8">
<Script Language ="JavaScript">
// JavaScript Appears here.
alert("这是第一个 JavaScript 例子!");
alert("欢迎你进入 JavaScript 世界!");
alert("今后我们将共同学习 JavaScript 知识!");
</Script>
</head>
</html>
Copy after login

Program running output:

JavaScript tutorial: Getting to know JavaScript for the first time


The above is the content of the JavaScript tutorial for getting to know JavaScript for the first time. For more related content, please pay attention to the PHP Chinese website (www.php.cn)!


Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
1 months ago By 尊渡假赌尊渡假赌尊渡假赌
Two Point Museum: All Exhibits And Where To Find Them
1 months ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Replace String Characters in JavaScript Replace String Characters in JavaScript Mar 11, 2025 am 12:07 AM

Detailed explanation of JavaScript string replacement method and FAQ This article will explore two ways to replace string characters in JavaScript: internal JavaScript code and internal HTML for web pages. Replace string inside JavaScript code The most direct way is to use the replace() method: str = str.replace("find","replace"); This method replaces only the first match. To replace all matches, use a regular expression and add the global flag g: str = str.replace(/fi

8 Stunning jQuery Page Layout Plugins 8 Stunning jQuery Page Layout Plugins Mar 06, 2025 am 12:48 AM

Leverage jQuery for Effortless Web Page Layouts: 8 Essential Plugins jQuery simplifies web page layout significantly. This article highlights eight powerful jQuery plugins that streamline the process, particularly useful for manual website creation

Build Your Own AJAX Web Applications Build Your Own AJAX Web Applications Mar 09, 2025 am 12:11 AM

So here you are, ready to learn all about this thing called AJAX. But, what exactly is it? The term AJAX refers to a loose grouping of technologies that are used to create dynamic, interactive web content. The term AJAX, originally coined by Jesse J

10 Mobile Cheat Sheets for Mobile Development 10 Mobile Cheat Sheets for Mobile Development Mar 05, 2025 am 12:43 AM

This post compiles helpful cheat sheets, reference guides, quick recipes, and code snippets for Android, Blackberry, and iPhone app development. No developer should be without them! Touch Gesture Reference Guide (PDF) A valuable resource for desig

Improve Your jQuery Knowledge with the Source Viewer Improve Your jQuery Knowledge with the Source Viewer Mar 05, 2025 am 12:54 AM

jQuery is a great JavaScript framework. However, as with any library, sometimes it’s necessary to get under the hood to discover what’s going on. Perhaps it’s because you’re tracing a bug or are just curious about how jQuery achieves a particular UI

10 jQuery Fun and Games Plugins 10 jQuery Fun and Games Plugins Mar 08, 2025 am 12:42 AM

10 fun jQuery game plugins to make your website more attractive and enhance user stickiness! While Flash is still the best software for developing casual web games, jQuery can also create surprising effects, and while not comparable to pure action Flash games, in some cases you can also have unexpected fun in your browser. jQuery tic toe game The "Hello world" of game programming now has a jQuery version. Source code jQuery Crazy Word Composition Game This is a fill-in-the-blank game, and it can produce some weird results due to not knowing the context of the word. Source code jQuery mine sweeping game

How do I create and publish my own JavaScript libraries? How do I create and publish my own JavaScript libraries? Mar 18, 2025 pm 03:12 PM

Article discusses creating, publishing, and maintaining JavaScript libraries, focusing on planning, development, testing, documentation, and promotion strategies.

jQuery Parallax Tutorial - Animated Header Background jQuery Parallax Tutorial - Animated Header Background Mar 08, 2025 am 12:39 AM

This tutorial demonstrates how to create a captivating parallax background effect using jQuery. We'll build a header banner with layered images that create a stunning visual depth. The updated plugin works with jQuery 1.6.4 and later. Download the

See all articles