$ _SERVER ['HTTP_REFERER']出错

Question

i just tried

echo $_SERVER['HTTP_REFERER'];

but it returned an error

Notice: Undefined index: HTTP_REFERER in C:\Program Files\....

What is the problem an why is it showing an error.

Answer 1

This is because HTTP_REFERER is not set you can try

if(isset($_SERVER['HTTP_REFERER']))
    echo $_SERVER['HTTP_REFERER'];
else
    echo 'HTTP_REFERER in not set';