如果http：//在字符串中则保留，否则如果不添加它

Question

I have a input that you enter a URL, i basically want to write some php that says if the domain containts "http://" then leave it be, else if not then add it to the beginning. This is what I have so far...

$domain = $_POST["domain"];

if (strpos($domain, "http://")) {
return $domain;
} else {
$domain = "http://" . $domain;
}

This doesnt seem to work..

it doesnt add the http:// on if it doesnt contain http://.

Answer 1

"http://" then leave it be, else if not then add it to the beginning.

How about adding adding it regardless? I find that to be easier:

<?php
$url = 'http://www.google.com';
echo 'http://' . preg_replace( '~^http://~', '', $url );