strpos() doesn't return a truthy value when the match is found at the start of the string

Question

I am attempting to clean up my URLS in the database, however I am literally having a brain-fart. This is PHP 101 level stuff, but I seriously cannot figure out what's wrong with the following snip:

<?php

$domain = 'http://www.example.com';

echo "\n\n\e[31mBeginning Domain is: $domain\n";

if (strpos($domain, '//')){
    $domain = explode( '//', $domain)[1];
    echo "\n\e[33mRemoving HTTP\n";
}

echo "\n\n\e[35mAfter first IF domain is: $domain\n";

if (strpos($domain, "www.")){
    echo "\n\e[33mREMOVING WWW\n";
    $domain = explode( "www.", $domain)[1];
}

echo "\n\n\e[35mAfter second IF domain is: $domain\n";

die("\n\n\e[31m$domain\n\n");

When run .. I am expecting a "clean" example.com -- However my output looks like:

Beginning Domain is: http://www.example.com

Removing HTTP

After first IF domain is: www.example.com

After second IF domain is: www.example.com

www.example.com

Why is if (strpos($domain, "www.")){ not entering the if ?

Answer 1

Why not debug the code properly? strpos($domain, "www.") returns 0 as long as $domain starts with www, and that evaluates to false.

By properly checking whether strpos($domain, "www.") returns exactly false, you can fix your algorithm