When the src value of the img label of a non-IE browser is null, two request problems occur.

When the img src value is null, two requests

Some people have encountered similar situations before. When there is a tag similar to , an extra request will be made to the page,

According to the analysis in an article, I guess whether all tags that will actively introduce external files will have such problems, such as embed and link,

Therefore, it is verified by experiment.

The following is a preliminary conclusion:

Tag/request count/Browser	IE	FF, safari, chrome
Img	2	2
Embed	1	2
Background: url	1	2
Link	1	2
Input type = 'image'	2	2
Script	1	2
Bgsound	2	-

 

Note:

1. The two request pages of IE and firefox are different.
IE: the requested file is locatedDirectory,For example, when the img tag, 2 requests are http://www.xxxx.cn/test/

FF, safari, chrome: Requests the accessed file

2. For the embed label, the preceding description indicates that when the type is not empty and the type is null, the FF request 1 and IE are different based on the type value.

3. If the above label does not contain "src =" ", there will be no second request.