显示未定义变量的Php错误：文件，未知错误

Question

Beginner in PHP

Below is my code for retrieving files from a folder, but it is showing me the error

Undefined variable: files 

Why i am getting this error.

It is an image gallery. Gallery folder does not have any image till now.

<?php
    if($theRugz<>''){
        /* settings */
        $image_dir = 'gallery/'.$theRugz.'/';
        $per_column = 5;
        $count = 0;

        if($theRugz=='11'){$rugType='Tufted';}else
        if($theRugz=='12'){$rugType='Loom Knotted';}else
        if($theRugz=='13'){$rugType='Indo Nepali';}else
        if($theRugz=='14'){$rugType='Shaggy Carpets';}else
        if($theRugz=='15'){$rugType='Cotton Kellims';}else
        if($theRugz=='16'){$rugType='Hemp and Soumak';}else
        if($theRugz=='17'){$rugType='Kellims Dhurries';}else
        if($theRugz=='18'){$rugType='Cotton Rugs';}else
        if($theRugz=='19'){$rugType='Bathmats';}else
        if($theRugz=='21'){$rugType='Chindi Rugs';}else
        if($theRugz=='22'){$rugType='Hand Knotted';}        

        if($_SESSION['SESS_CLIENT']==1){
            /* Files for all */
            /* step one:  read directory, make array of files */
            if ($handle = opendir($image_dir)) {
                while (false !== ($file = readdir($handle))) 
                {
                    if ($file != '.' && $file != '..') 
                    {
                        if(strstr($file,'-thumb') or strstr($file,'-tuhmb'))
                        {
                            $files[] = $file;
                        }
                    }
                }
                closedir($handle);
            }
            /* Step One End */
            /* step two: loop through, format gallery */
            if(count($files))
            {
                echo '<p class="head1">Range of '.$rugType.' (click on thumbnail to enlarge)</p>';
                foreach($files as $file)
                {
                    $count++;
                    if(strstr($file,'-tuhmb')){
                    echo '<a class="photo-link" rel="one-big-group" href="',$image_dir,str_replace('-tuhmb','',$file),'"><img src="',$image_dir,$file,'" width="183" height="130" alt="'.str_replace('-tuhmb.jpg','',$file).'" title="'.str_replace('-tuhmb.jpg','',$file).'" class="img-thumb" /></a>'.PHP_EOL;
                    }else{
                    echo '<a class="photo-link" rel="one-big-group" href="',$image_dir,str_replace('-thumb','',$file),'"><img src="',$image_dir,$file,'" width="183" height="130" alt="'.str_replace('-thumb.jpg','',$file).'" title="'.str_replace('-thumb.jpg','',$file).'" class="img-thumb" /></a>'.PHP_EOL;
                    }
                    if($count % $per_column == 0) { echo '<div class="clear"></div>'; }
                }
            }
            else
            {
                echo '<p>There are no images in this gallery.</p>';
            }
            /* Step two End */
        }else{
            /* Files for all */
            /* step one:  read directory, make array of files */
            if ($handle = opendir($image_dir)) {
                while (false !== ($file = readdir($handle))) 
                {
                    if ($file != '.' && $file != '..') 
                    {
                        if(strstr($file,'-thumb'))
                        {
                            $files[] = $file;
                        }
                    }
                }
                closedir($handle);
            }
            /* Step One End */
            /* step two: loop through, format gallery */
            if(count($files))
            {
                echo '<p class="head1">Range of '.$rugType.' (click on thumbnail to enlarge)</p>';
                foreach($files as $file)
                {
                    $count++;
                    echo '<a class="photo-link" rel="one-big-group" href="',$image_dir,str_replace('-thumb','',$file),'"><img src="',$image_dir,$file,'" width="183" height="130" alt="'.str_replace('-thumb.jpg','',$file).'" title="'.str_replace('-thumb.jpg','',$file).'" class="img-thumb" /></a>'.PHP_EOL;
                    if($count % $per_column == 0) { echo '<div class="clear"></div>'; }
                }
            }
            else
            {
                echo '<p>There are no images in this gallery.</p>';
            }
            /* Step two End */
        }
    }

    ?>

Answer 1

$files is undefined means that you use a variable that you didn't defined (obviously).

By looking briefly at your code I can see that the variable files is being used inside a loop $files[] = $file;. You should ask yourself, why is this variable is undefined?

The answer is pretty much simple - the loop or the condition never runs. In order for the mentioned above line to get executed your code should fulfill 4 conditions (3 if and a while loop).

if ($handle = opendir($image_dir)) {
                while (false !== ($file = readdir($handle))) 
                {
                    if ($file != '.' && $file != '..') 
                    {
                        if(strstr($file,'-thumb') or strstr($file,'-tuhmb'))
                        {

Track your code and locate the condition that returns false and preventing your code from getting into the $files[] = ... line.

Anyway, declaring that variable at the beginning of the code will prevent that error from appearing. Since you're using it as an array:

$files = array();