How can PHP handle cases where the same link appears multiple times in a file and avoid processing duplicates?

To handle cases where the same link appears multiple times in a file and avoid processing duplicates, we can use an array to keep track of the links that have already been processed. Before processing a link, we can check if it exists in the array and skip it if it does.

$processedLinks = array();

// Assuming $links is an array of links extracted from the file
foreach ($links as $link) {
    if (!in_array($link, $processedLinks)) {
        // Process the link here
        
        // Add the link to the processed array
        $processedLinks[] = $link;
    }
}