How do i name my files 00, 01, 02 and so on in PHP

I have some files i want to upload. And when i upload them, i want the first to be numbered 00, the second to be numbered 01. I wrote a function to get the newest number, but of course, this ain't workin

$i = 00;
while($i < $filecount)
{
    if(!file_exists("../photo/$i.jpg"))
 开发者_开发问答   {

         return $i;
         print($i);
    }
    else if(file_exists("../photo/$i.jpg")) {
        $i = $i + 01;
    }

But now, when i upload a file, it just numbers it: 0, 1, 2, 3.

I got some new code :

 function getFileNumber() {
            $i = 0;
            while ($i < $filecount) {

                $fn = sprintf("../photo/%02d.jpg", $i); 
                if (!file_exists($fn)) {

                    return $i;
                } else {
                    $i ++;
                }
            }
        }

But it returns 00 every time, but i want to to go 00,01,02,03. Somebody any ideas?

Integer literals don't contain any formatting. 1 is the value one, it can't be "01", that's a formatting problem. As such, format your numbers:

$file = sprintf('%2u.jpg', $i);

You can use

echo str_pad($i, 2, "0", STR_PAD_LEFT);

Additionally, your print() after the return will never be executed and use if/else instead of if/elseif.

Check out sprintf() that allows for pretty flexible string formatting - especially check out the padding and width specifiers. You're looking for something along the lines of

$i = 0;
while ($i < $filecount)
{
    $fn = sprintf("../photo/%02d.jpg", $i);
    if (!file_exists($fn))
    {
         return $i;
    }
    else {
        $i++;
    }
}

1. print($i) is a dead code - it will never get executed
2. Second, you don't need to check else if(file_exists("../photo/$i.jpg")) again.
3. 00 is not valid integer, it's simplified to just 0, as 01 simplified to 1 (actually it's treated as octal digits, so 08 and 09 is invalid)

So, to have the real 00, 01, 02 you'll have to format your output with spritf

$q=0;
$file_suffix = sprintf("%02d", $q);
if(!file_exists("../photo/{$file_suffix}.jpg")){
     print($i);
     return $i;
}
else{
    $q+=1;
}