首页 > 代码库 > 【JavaScript】笔记01——Making Stuff Happen???

【JavaScript】笔记01——Making Stuff Happen???

While, generally speaking, HTML is for content and CSS is for presentation, JavaScript is for interactivity.

 1、从HTML到JavaScript,像下面这样:

<!DOCTYPE html><html>    <head>        <meta charset="UTF-8">        <title></title>    </head>    <body>        <script>            alert("Hello, world.");        </script>    </body></html>

alert的意思是警告,类似于message. 效果上就是弹出一个对话框。

 

2、引用外部的.js文件

<!DOCTYPE html><html>    <head>        <meta charset="UTF-8">        <title></title>    </head>    <body>        <script src="http://www.mamicode.com/script.js"></script>    </body></html>

script.js

alert("Hello, world.");

 

3、在浏览器Console中运行JavaScript代码,Chrome进入Console的快捷键是F12

技术分享

 

4、在正式开始学习前,需要强调的是:

A browser then runs JavaScript line-by-line, starting at the top of the file or script element and finishing at the bottom (unless you tell it to go elsewhere).

 

5、询问用户姓氏的小程序

<!DOCTYPE html><html>    <head>        <meta charset="UTF-8">        <title></title>    </head>    <body>        <script type="text/javascript">            var surname = prompt(‘Greetings friend, may I enquire as to your surname?‘);        </script>    </body></html>

通过浏览器运行这段代码,将跳出一个“小盒子”,询问你的姓氏。

 

6、变量类似于一个“盒子”,我们利用它来储存数据;它具有“名”和“值”。

声明(Declaration)

var surname;var age;

初始化(Initialization)

var name = "Tom";

赋值(assignment)

name = "Andy";age = 43;

 

【JavaScript】笔记01——Making Stuff Happen???