Strict Standards: "Only variables should be passed by reference" - php

Question

In the php function below I have on line 31 the error "Strict Standards: Only variables should be passed by reference"
As I read the answers on the forum I must change the explode(..). But I don’t have any idea how..
function scanDirectoryImages($directory, array $exts = array('jpeg', 'jpg', 'png'))
{
if (substr($directory, -1) == 'uploads/') {
$directory = substr($directory, 0, -1);
}
$html = '';
if (
is_readable($directory)
&& (file_exists($directory) || is_dir($directory))
) {
$directoryList = opendir($directory);
while($file = readdir($directoryList)) {
if ($file != '.' && $file != '..') {
$path = $directory . '/' . $file;
if (is_readable($path)) {
if (is_dir($path)) {
return scanDirectoryImages($path, $exts);
}
if (
is_file($path) && in_array(end(explode('.', end(explode('/', $path)))), $exts) // Line 31
) {
$html .= '<a href="' . $path . '"><img src="' . $path
. '" style="max-height:100px;max-width:100px" /></a>';
}
}
}
}
closedir($directoryList);
}
return $html;
}

Answer 1

According to the PHP Manual for end:
This array is passed by reference because it is modified by the function. This means you must pass it a real variable and not a function returning an array because only actual variables may be passed by reference.
Parameter should be sent as an array variable only.
ToDo:
Break this statement inside if:
is_file($path) && in_array(end(explode('.', end(explode('/', $path)))), $exts)
to something like this:
$path1 = explode('/', $path);
$path2 = end($path1);
$path3 = explode('.', $path1);
$path4 = end($path3);
is_file($path) && in_array($path4, $exts)
Alternatively,
Since you are getting extension from the path, you can use pathinfo:
pathinfo($path)['extension']

Answer 2

You can try this code:
<?php
<?php
function scanDirectoryImages($directory, array $exts = array('jpeg', 'jpg', 'png'))
{
if (substr($directory, -1) == 'uploads/') {
$directory = substr($directory, 0, -1);
}
$html = '';
if (
is_readable($directory)
&& (file_exists($directory) || is_dir($directory))
) {
$directoryList = opendir($directory);
while($file = readdir($directoryList)) {
if ($file != '.' && $file != '..') {
$path = $directory . '/' . $file;
if (is_readable($path)) {
if (is_dir($path)) {
return scanDirectoryImages($path, $exts);
}
$path_info = pathinfo($path);
$ext = strtolower($path_info['extension']);
if (is_file($path) && in_array($ext, $exts)) {
$html .= '<a href="' . $path . '"><img src="' . $path
. '" style="max-height:100px;max-width:100px" /></a>';
}
}
}
}
closedir($directoryList);
}
return $html;
}

Answer 3

try to separate your code in the if statement like this, this should work :
// other code
if (is_dir($path)) {
return scanDirectoryImages($path, $exts);
}
$explode_1 = explode('/', $path);
$explode_2 = explode('.', end($explode_1));
if (is_file($path) && in_array(end($explode_2), $exts)) {
// the rest of the code