这是PHP中的错误吗？

<?php

if(stripos('http://cp.uctorrent.com', 'cp.utorrent.com') >= 0){
    echo "Good1";
}else{
     echo "Bad1";
}

if(stripos('http://uctorrent.com', 'cp.utorrent.com') >= 0){
    echo "Good2";
}else{
    echo "Bad2";
}

?>

output is

Good1Good2

whereas it should be

Good1Bad2

utorrent <---> uctorrent

i am such an idiot...

it was spell mistake ...

comparing uctorrent with utorrent

sorry every one

<?php
  if(false >= 0) echo "Good";
  else echo "Bad";
  // this code prints Good
?>

It's not a bug, it's a "weird" boolean conversion.

stripos returns false when the string is not found, and false converts to 0 in PHP.

Directly from the documentation (the problem is the other way around) :

Warning This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE, such as 0 or "". Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

In case 2 stripos returns false as the search fails and false when compared with 0 returns true.

The right way of doing it is to use the identity operator which checks both type and value:

if(stripos('http://cp.uctorrent.com','cp.utorrent.com') !== false)
  echo "Good1";                                         ^^^^^^^^^^
else 
  echo "Bad1";

If needle is not found, stripos() will return boolean FALSE.

http://php.net/manual/en/function.stripos.php

Boolean FALSE in PHP is equivalent to integer 0, which is >= 0.

If you want to check whether stripos failed to get a match, you need to test for type and value with !== or ===, for example:

<?php

if(stripos('http://cp.uctorrent.com','cp.utorrent.com')!==false)echo "Good1";
else echo "Bad1";

if(stripos('http://uctorrent.com','cp.utorrent.com')!==false)echo "Good2";
else echo "Bad2";

?>

Reading the manual would help greatly:

Warning

This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE, such as 0 or "". Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

Again, try this and avoid the issues caused by microoptimization function use patterns:

if (stristr('http://cp.uctorrent.com', 'cp.utorrent.com')) {
   echo "Good1";
}
else {
   echo "Bad1";
}

Below $p has value 'false' (means 0), so it's >=0

$p = stripos('http://uctorrent.com','cp.utorrent.com');

You need to check stripos('http://uctorrent.com','cp.utorrent.com') !== false first then get $p (found position) like above...