php_file_zip.php

<?php
function create_zip(array $files, string $destination, bool $overwrite = false): bool 
    {
        // If the zip file already exists and overwrite is false, throw an exception
        if (file_exists($destination) && !$overwrite) {
            throw new Exception("Zip file already exists and overwrite is false.");
        }
        // Filter out any non-existing files
        $valid_files = array_filter($files, "file_exists");
        // If we have valid files...
        if (count($valid_files)) {
            // Create the archive
            $zip = new ZipArchive();
            if ($zip->open($destination, $overwrite ? ZipArchive::OVERWRITE : ZipArchive::CREATE) !== true) {
                throw new Exception("Cannot open the zip archive.");
            }
            // Add the files
            foreach ($valid_files as $file) {
                $zip->addFile($file, basename($file));
            }
            // Close the zip -- done!
            $zip->close();
            // Check to make sure the file exists
            return file_exists($destination);
        } else {
            throw new Exception("No valid files provided.");
        }
    }