Better way of comparing substrings than a giant if loop

Question

Alright so, in my code, I have a URL, and it gets passed into my function: testURL($url), which, in order:

1. Tests the base url whether it's the domain ('http://www.example.com')

2. Tests the various substrings:

   • ShowForum
   • Amex
   • Owners
   • ManagementCenter
   • WeatherUnderground
   • MapPopup
   • asp
   • pages

3. Returns true if it has the base url, but doesn't match the substrings, otherwise return false;

Here's the code

function testURL($url){
    if ((substr($url, 0, 23) == "http://www.example.com/") && (substr($url, 23, 3) != "asp") && (substr($url, 23, 4) != "Amex") && (substr($url, 23, 5) != "pages")  && (substr($url, 23, 16) != "ManagementCenter") && (substr($url, 23, 16) != "Owners")  && (substr($url, 23, 9) != "ShowForum") && (substr($url, 23, 8) != "MapPopup") && (substr($url, 23, 18) != "WeatherUnderground")) {
      return false;
    } else {
      return true;  
    }

Example:

testURL('http://www.example.com/Amex'); --> returns true
testURL('http://www.example.com/PayPal'); --> returns false

It's called in my case like:

if (testURL('http://www.example.com/Visa')){
  return;
}

The banned substrings list will get bigger as time goes on. So, is there a better way to match substrings of variable lengths then that giant if-else loop?

Thanks in advance!

Answer 1

This should work for you:

(Here I just parse the url with parse_url(), where then I check if the host matches and also if the path isn't in the array with in_array())

<?php

    function testURL($url) {
        $parsed = parse_url($url);
        if($parsed["host"] == "www.example.com" && !in_array(explode("/", $parsed["path"])[1], ["asp", "Amex", "WeatherUnderground", "MapPopup", "ShowForum", "Owners", "ManagementCenter", "pages"]))
            return false;
        else
            return true;
    }

?>