php - 如何摆脱这个奇怪的“空分隔符”消息

Question

I have some code that uses the stristr function to extract data I need.

It gives me this Warning for every iteration of the loop:

Warning: stristr() [function.stristr]: Empty delimiter in ... line 55

The code works apart from this Warning. Here is the code:

$data = stristr("$text", "$key");
$result = string_limit_words($data,2);
print "$result<BR>";

How do I get rid of the warning message?

Answer 1

$data = $text;
if($key)
   $data = stristr($data, $key);
$result = string_limit_words($data,2);
print "$result<BR>";

Basically only do the stristr if the $key (the needle) is not an empty string

Answer 2

1. You haven't shown us the loop. I assume that the code you posted is in the body of the loop
2. Why use "$variable" ? Quotationmarks are not required here.
3. You can suppress warnings by writing @functionName();
4. Check if the needle is empty before applying it
5. HTML (< BR>) should be lowercase

Answer 3

Quote from php.net stristr user: dpatton.at.confluence.org

There was a change in PHP 4.2.3 that can cause a warning message to be generated when using stristr(), even though no message was generated in older versions of PHP.

The following will generate a warning message in 4.0.6 and 4.2.3:

stristr("haystack", "");

OR

$needle = "";  
stristr("haystack", $needle);

This will not generate an "Empty Delimiter" warning message in 4.0.6, but will in 4.2.3:

unset($needle); 
stristr("haystack", $needle);

Here's a URL that documents what was changed