php删除部分字符串

Question

Why does this not remove the http:// of the string?

$rurl = 'http://www.google.com';
$httpposi = strpos($rurl,'://');
echo $httpposi;
if($httpposi === true) {
$url=substr($rurl, strpos($rurl, '://') + 3);
echo $url;
} else {
$url=$rurl;
echo '3'.$url.'2';
}

echo $url;

Answer 1

Instead of:

if($httpposi === true) {

you need:

if($httpposi !== false) {

since if it is found in the string, it will return an offset as an integer, and you are doing a strict comparison and strictly an non-zero, positive integer is not equal to the boolean value true.

8 == true // true
8 === true // false, because 8 is not a boolean
0 == true // false, but we need to know if the needle is at position 0

so:

0 !== false // true, string was found
8 !== false // true, string was found
false !== false // false, string was not found

If the sequence is found at the beginning of the string, the falsy 0 will be returned, thus the need to strictly compare to false to know that it has not been found at all.

http://ideone.com/QXBs7