JavaScript Study Notes (11)_Basic Knowledge
document对象
下表列出了BOM的document对象的一些通用属性：
|
属 性 |
说 明 |
|
alinkColor |
激活的链接的颜色，如 定义的* |
|
bgColor |
页面的背景颜色，如 定义的* |
|
fgColor |
页面的文本颜色，如 定义的* |
|
lastModified |
最后修改页面的日期，是字符串 |
|
linkColor |
链接的颜色，如 定义的* |
|
referrer |
浏览器历史中后退一个位置的URL |
|
title |
|
|
URL |
当前载入的页面的URL |
|
vlinkColor |
访问过的链接的颜色，如 定义的* |
* 反对使用这些属性，因为它们引用了
document对象也有许多集合，提供对载入的页面各个部分的访问。下表列出了这些集合：
|
集 合 |
说 明 |
|
anchors |
页面中所有锚的集合 |
|
applets |
页面中所有applet的集合 |
|
embeds |
页面中所有嵌入式对象的集合（由标签表示） |
|
forms |
页面中所有表单的集合 |
|
images |
页面中所有图像的集合 |
|
links |
页面中所有链接的集合 |
与window.frame集合相似，可用数字或名字引用document对象的每个集合，也就是说可用document.images[0]或document.images["图片的name"]访问图像。
location对象
location对象表示载入窗口的URL，此外它还可以解析URL。
hash——如果URL包含#，该方法将返回该符号之后的内容（例如，http://www.somewhere.com/index#selection1的hash等于"#selection1"）。
host——服务器的名字（如www.wrox.com）。
hostname——通常等于host，有时会省略前面的www。
href——当前载入的页面的完整URL。
pathname——URL中主机名后的部分。例如，http://www.somewhere.com/pictures/index.htm的pathname是"/pictures/index.htm"。
port——URL中声明的请求的端口。默认情况下，大多数URL没有端口信息，所以该属性通常是空白的。像http://www.somewhere.com:8080/index.htm这样的URL的port属性等于8080。
protocol——URL中使用的协议，即双斜杠（//）之前的部分。例如，http://www.somewhere.com中的protocol属性等于http:，ftp://www.somewhere.com的protocol属性等于ftp:。
search——执行GET请求的URL中的问号（?）后的部分，又称为查询字符串。例如，http://www.somewhere.com/abc.htm?term=javascript中的search属性等于?term=javascript
跳转到一个页面，但是不想从浏览器历史中访问，即不能后退回来，可以使用方法location.replace("http://www.baidu.com")方法。
navigator对象
检测浏览器的版本、所支持的MIME类型、已安装的外挂程序（plug-in）。该对象包含两个子对象：外挂对象、MIME类型对象。
|
appCodeName |
代码 |
|
appName |
名称 |
|
appVersion |
版本 |
|
language |
语言 |
|
mimeType |
以数组表示所支持的MIME类型 |
|
platform |
编译浏览器的机器类型 |
|
plugins |
以数组表示已安装的外挂程序 |
|
userAgent |
用户代理程序的表头 |
screen object
Thescreen object contains screen information, usually including the following attributes (however, many browsers have added their own attributes):
height - The height of the screen, in pixels.
width – The width of the screen, in pixels.
availHeight - The height of the screen (in pixels) that the window can use, minus the width of the taskbar, changes with the user's taskbar and does not change with the window. This includes the space required for operating system elements such as Windows toolbars.
availWidth - The width of the screen (in pixels) that the window can use, minus the height of the taskbar, varies with the user's taskbar.
colorDepth – The color depth of the user's screen, in bits per pixel. In fact, it is the number of bits representing the color. Most systems use 32-bit.
The availHeight and availWidth properties are useful when determining the size of a new window. For example, you can use the following code to populate the user's screen:
moveTo(0,0);
resizeTo(screen.availWidth,screen,availHeight);
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