如何捕获文件名错误的错误？ [重复]

I am working on an instagram clone for school and I am currently working on the "update profile" feature,whenever I try to update the profile picture it works like a charm, but whenever I dont update the profile picture but I just update the description or username I get the following error.

"getimagesize(): Filename cannot be empty"

What is the best way to catch this error when I am not uploading a new profile picture?

I have tried a "try catch" method but it doesn't seem to work. (could be possible I implemented it the wrong way

    if(isset($_FILES["file"])){
        if(getimagesize($_FILES["file"]["tmp_name"]) !== false){
            $target_dir = "uploads/";
            $extention = explode(".", $_FILES["file"]["name"]);

            $i = count($extention) - 1;
            $target_file = $target_dir . basename($_FILES["file"]["tmp_name"] . "." . $extention[$i]);

            if (move_uploaded_file($_FILES["file"]["tmp_name"], $target_file)) {
                // File has been moved to Uploads/[temp_name].[extention]
                $user->setImage($target_file);
                $a["image"] = $target_file;
            } else {
                // The file did not move to the destonation folder
            }
        }
    }

I expect this to not return the error to me when I am not uploading a new picture but just tring to update my username or description.

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You can check if error index is zero (UPLOAD_ERR_OK), if error is not zero cause no file was uploaded, UPLOAD_ERR_NO_FILE will be there

If you just want to check if upload went good you can write:

if ($_FILES['file']['error'] == UPLOAD_ERR_OK) {
    // file is good (and not an error)
}

If you want to check file wasn't uploaded

if ($_FILES['file']['error'] == UPLOAD_ERR_NO_FILE) {
    // file is empty, no upload
}

Check PHP Reference for more!