Types of URLs

问题:

1) Absolute
http://www.example.com/images/icons.png

2) Relative
../images/icons.png

3) ???
/images/icons.png

4) ???
//www.example.com/images/icons.png

Do URL types 3 and 4 have a name? One place I've seen type 4 being used is at slashdot.

回答1:

1. Absolute http://www.example.com/images/icons.png
2. Document-Relative ../images/icons.png
3. Root-Relative /images/icons.png
4. Protocol-Relative //www.example.com/images/icons.png

For #4, I've also often called them "Protocol-Agnostic"

回答2:

Type 1 is just a "URI" (sometimes called an "absolute URI").

For types 2, 3 and 4 the definitive answers are in RFC 3986, section 4.2.

They are all "relative references", but according to the RFC are qualified thus:

• ../images/icons.png - "relative path reference"
• /images/icons.png - "absolute path reference"
• //.../icons.png - "network path reference"

The latter is often used if you want to specify a URL containing a domain name, but where you want the protocol to match the protocol used to access the current resource. For example, if your images are downloaded from a CDN, you could use this to default to https if the current page was also downloaded via https, thus preventing the warning about including non-secure resources in a secure page.

回答3:

number 3 is also considered relative. number 4 is absolute, but lacks the protocol. This is useful, if you want to be able to access the same URL using HTTP and HTTPS.

Absolute URLs specify the location of a Web page in full, and work identically no matter where in the world you are.

Relative URLs are context-sensitive, giving a path with respect to your current location.

回答4:

Type three is root-relative.

Dunno about 4.

回答5:

Absolute Url gives out directly the location of the file/document you are looking for. example:"http:/www.otagasue.com/images/coolpics.jpg" Relative Urls normally points a file/document in relation ti the current location of the file.unlike absolute thet are short urls referring to root directory example"...otagasue/pica.jpg"

frm otaga.