## How to Efficiently Detect URLs within a String Using PHP?

Determining String Presence within an Array

You aim to verify if a user-submitted string contains any URLs stored in a prédéfined array. To do so, you've attempted to employ the in_array() function, but it consistently returns "Match not found" regardless of the input.

Corrected Approach

The issue lies in using in_array() for this task. This function assesses the presence of an entire string within an array, rather than matching partial values. To check for string inclusion, consider the following alternatives:

1. strpos():

   <code class="php">if (strpos($string, $url) !== FALSE) {
       echo "Match found"; 
       return true;
   }</code>

   This function searches for the occurrence of $url within $string. A non-FALSE strpos result indicates a match, and the echo and return statements accordingly signify and return "Match found".

2. strstr():

   <code class="php">if (strstr($string, $url)) {
       echo "Match found"; 
       return true;
   }</code>

   strstr() effectively accomplishes the same operation as strpos(). It returns the portion of $string that contains $url, and a non-FALSE result again implies a successful match.

Iterating through the Array

Since you want to check against multiple URLs in the array, employ a foreach loop to iterate through each element:

<code class="php">foreach ($owned_urls as $url) {
    if (strpos($string, $url) !== FALSE) { // or strstr($string, $url)
        echo "Match found"; 
        return true;
    }
}</code>

This loop explores each URL, and if any matches the string, it terminates the loop, displays "Match found", and returns true. Alternatively, upon concluding without finding a match, the script echoes "Not found!" and returns false.

Case Sensitivity

If the string and URLs are not case-sensitive, utilize stripos() or stristr() functions, respectively. These case-insensitive versions ensure the matches are case-independent.

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