What function can be used to read all images from a folder in PHP?

To read all images from a folder in PHP, you can use the `scandir()` function to get a list of all files in the directory, and then filter out only the image files based on their file extensions. You can use functions like `pathinfo()` to check the file extension and determine if it is an image file.

$folder = 'path/to/folder';
$files = scandir($folder);

foreach ($files as $file) {
    $fileInfo = pathinfo($file);
    $extension = strtolower($fileInfo['extension']);
    
    if (in_array($extension, ['jpg', 'jpeg', 'png', 'gif'])) {
        echo '<img src="' . $folder . '/' . $file . '" alt="' . $file . '">';
    }
}