Question

I’m trying to display two randomly selected images from a dir

Instead of images, img.names are displayed

$dir    = 'memb_area/captcha/imgs/';
$files = scandir($dir);
$rand_keys = array_rand($files, 2);
echo $files[$rand_keys[0]] . "\n";
echo $files[$rand_keys[1]] . "\n";  

Also tried:

echo '<img src="memb_area/captcha/imgs">' + 'echo $files[$rand_keys[0]] . "\n";'

And – is it possible to print these pictures inside a separate div on a page?

Answer 1

+ is not a valid PHP concatenation character. . is. By using +, you are effectively adding these two strings, which when converted to integers, equate to 0.

This line:
echo '<img src="memb_area/captcha/imgs">' + 'echo $files[$rand_keys[0]] . "\n";'

should be:(updated)
echo "<img src=\"memb_area/captcha/imgs/".$files[$rand_keys[0]]."\">".PHP_EOL;

Update 01: (OP’s Comment: but after refreshing, after two or three times – nothing is displayed. Next refresh – image is displayed… and so on.)

Scandir php.net (Example #1) says that:

Array
(
    [0] => .
    [1] => ..
    [2] => bar.php
    [3] => foo.txt
    [4] => somedir
)

So, maybe your scandir($foo) is returning an array with two keys having invisible directories as their values.

Try this code and let me know:

$dir    = 'memb_area/captcha/imgs/';
$files = scandir($dir);

if($files[0] == ".") unset($files[0]);
if($files[1] == "..") unset($files[1]);

$files = array_values($files); // reset array keys back to 0,1,2..

$rand_keys = array_rand($files, 2);
echo $files[$rand_keys[0]] . "\n";
echo $files[$rand_keys[1]] . "\n";  

echo "<img src=\"memb_area/captcha/imgs/".$files[$rand_keys[0]]."\">".PHP_EOL;