PHP build_url()

build_url.php

<?php

function build_url($parts)
{
    $result = '';

    if (isset($parts['scheme'])) {
        $result .= $parts['scheme'] . ':';
    }

   if (isset($parts['host'])) {

        $result .= '//';

        if (isset($parts['user'])) {
            $result .= $parts['user'];

            if (isset($parts['pass'])) {
                $result .= ':' . $parts['pass'];
            }

            $result .= '@';
        }

        $result .= $parts['host'];

        if (isset($parts['port'])) {
            $result .= ':' . $parts['port'];
        }
    }

    if (isset($parts['path'])) {
        $result .= $parts['path'];
    }

    if (isset($parts['query'])) {
        $result .= '?' . $parts['query'];
    }

    if (isset($parts['fragment'])) {
        $result .= '#' . $parts['fragment'];
    }

    return $result !== '' ? $result : false;
}