Php Warning: strstr () [function. strstr]: Empty delimiter

When using the strstr function in php today, the following error message is displayed: Warning: strstr () [function. strstr]: Empty delimiter. Later, the solution is found repeatedly. If you need it, you can refer to it.

Warning: strstr () [function. strstr]: Empty delimiter

Strange: Is there a problem with a parameter in strstr of the php function?

So I wrote a test example.

The Code is as follows:	Copy code
<? Php $ Text = "asdfghjklqwertyuiopzxcvbnm "; // $ Key = "g "; // According to the php error prompt Empty delimiter, it is determined that the value of $ text should not have a problem, so the key value is intentionally commented If (strstr ($ text, $ key )){ Echo "found it "; } Else { Echo "not found "; } ?>

Strstr () does not return an error. Therefore, the $ key value may be an empty string "". Just try again.

Sure enough, when strstr ($ text, "") is displayed, the error Warning: strstr () [function. strstr]: Empty delimiter is prompted.