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I want to make a PHP page with the Find image function, with id=xx,php in the URL to get the ID value with get. If a picture with the same file name and ID is found, it displays "Load.gif" if it is not found. I am pure novice, referring to the example of the Internet to write a paragraph, but there is no way to display pictures. Please guide the experts.
The code is as follows:

 
      $id =$_get["id"];
$filename = "/' $id '. gif";
if (file_exists ($filename)) {
echo ReadFile ($filename);
}
else {
echo ReadFile ('/load.gif ');
}
?>

------Solution--------------------
$filename = "/' $id '. gif";
Why do you want price quotes?
$filename = "/$id. gif";
------Solution--------------------
References:

I want to make a PHP page with the Find image function, with id=xx,php in the URL to get the ID value with get. If a picture with the same file name and ID is found, it displays "Load.gif" if it is not found. I am pure novice, referring to the example of the Internet to write a paragraph, but there is no way to display pictures. Please guide the experts.
The code is as follows:

   
        $id =$_get["id"];
$filename = "/' $id '. gif";
if (file_exists ($filename)) {
echo ReadFile ($filename);
}
else {
echo ReadFile ('/load.gif ');
}
?>

Wrote a demo to see.

$id = Isset ($_get[' id ')? $_get[' id ']: 0;

$filename = Intval ($id). ". GIF ";
if (file_exists ($filename)) {
    Echo ';
}else{
    Echo ';
}

