问如何在php中统计上传文件的数量

EN

<div id="dragAndDropFiles" class="uploadArea">
        <h1>Drop Images Here</h1>
    </div>
    <form id="sfmFiler" class="sfmform" method="post" enctype="multipart/form-data">
        <input type="file" name="file" id="file" multiple />
        <input type="submit" name="submitHandler" id="submitHandler" class="buttonUpload" value="Upload">
    </form>

if($_SERVER['REQUEST_METHOD'] == "POST") {
    $tmpFilePath = $_FILES['file']['tmp_name'];
    $newFilePath = $dir.'/' . $_FILES['file']['name'];
    if(move_uploaded_file($tmpFilePath, $newFilePath)) {
      echo "xxx files are successfully uploaded";
    }
}