if http:// is in string then leave it, else if not add it

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 beginn

Answer 1

Use caution when using strpos(). It will return 0 when 'http://' is found at the beginning of the string, causing your if statement to fail unexpectedly. You will want to check the type of the return to be sure:

$domain = $_POST["domain"];

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

Answer 2

Since the string starts with http://, strpos will return 0, which will evaluate to false.

Change the if statement to:

if(strpos($domain, "http://") !== FALSE){

Answer 3

if (strpos($domain, "http://") !== false) {
//return substr($domain,7); Thanks Rocket. 
return $domain;
} else {
return "http://" . $domain;
}

Answer 4

That is because strpos will return the location of the string, within the string. In your url, that is 0. Which equals to false. Make it a strict check - add === false.

Answer 5

read manual:

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.

Answer 6

"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 );