Use Javascript to determine whether an image exists. If the image does not exist, the default image code is displayed.

The onerror event of the image object is used to determine whether to change the src of the image object to the URL of the default image.
<P> first case: The image exists and is displayed normally </p> <p> second case: The image does not exist. The default image is displayed. </p>
[Ctrl + A select all Note: If you need to introduce external Js, You need to refresh it to execute]

The following is a js judgment
Use javascript to determine whether a specified image file exists:
For example, judge whether the image address exists.
If the image does not exist, the image will be detected again several seconds later. If the address is valid, the system will prompt that the address is valid.
Copy codeThe Code is as follows:
<Script type = "text/javascript">
Function IsExist (url)
{
X = new ActiveXObject ("Microsoft. XMLHTTP ")
X. open ("HEAD", url, false)
X. send ()
Return x. status = 200
}
Alert (IsExist ("http://www.bkjia.com/uploads/allimg/131015/14542G5b-1.gif "))
</Script>

If the image exists, true is returned.
Copy codeThe Code is as follows:
<SCRIPT language = "javascript">
Var xmlhttp = new ActiveXObject ("Msxml2.XMLHTTP ");
Xmlhttp. Open ("GET", "http://www.bkjia.com/uploads/allimg/131015/14542G5b-1.gif", false );
Xmlhttp. Send ();
Alert (xmlhttp. responseText );
</SCRIPT>

If the image exists, GIF89aX is returned.
Copy codeThe Code is as follows:


Because the image does not exist, the returned image does not exist!