Php 多个文件无法正常工作时的文件上载

我的代码有一个奇怪的问题：

有三个输入

文件
标记。以下是上传场景及其结果：

所有三个文件同时出现-成功
唯一的图片-成功
只有音频故障
只有视频故障
一张图片和一个音频-图片成功，音频失败
一张图片和一个视频-图片成功，视频失败
一个音频和一个视频-其中一个成功

<?php 
session_start(); 
if(!isset($_SESSION["username"])){
    header('Location: index.php');
}
if(isset($_POST["year"])){
    ini_set('display_errors',1);
    error_reporting(E_ALL);
    var_dump($_FILES);
    $year = $_POST["year"];
    $height = $_POST["height"];
    $weight = $_POST["weight"];
    $school = $_POST["school"];
    $class = $_POST["class"];
    $target_dir_img = "./pictures/";
    $target_dir_aud = "./audios/";
    $target_dir_vid = "./videos/";

    $uploadOk = 1;

    $target_files = array();

    $target_img = basename($_FILES['uploadedFiles']['name'][0]);
    var_dump($target_img);
    if(strcmp($target_img,'')){
        $imageFileType = pathinfo($target_img,PATHINFO_EXTENSION);

        $newImageName = $target_dir_img . $_SESSION['username']."_".$_POST['year'].".". $imageFileType;

        if($imageFileType != "jpg" && $imageFileType != "jpeg") {
            echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";
            $uploadOk = 0;
        }
        else {
            $target_files[] = $newImageName;
        }
    }

    // Allow certain file formats

    $target_aud = basename($_FILES['uploadedFiles']['name'][1]);
    var_dump($target_aud);
    if(strcmp($target_aud,'')) {

        $audioFileType = pathinfo($target_aud, PATHINFO_EXTENSION);

        $newAudioName = $target_dir_aud . $_SESSION['username']."_".$_POST['year'].".". $audioFileType;

        if($audioFileType != "mp3") {
            echo "Sorry, only MP3 files are allowed.";
            $uploadOk = 0;
        }
        else {
            $target_files[] = $newAudioName;
        }
    }

    $target_vid = basename($_FILES['uploadedFiles']['name'][2]);
    var_dump($target_vid);
    if(strcmp($target_vid,'')){

        $videoFileType = pathinfo($target_vid, PATHINFO_EXTENSION);

        $newVideoName = $target_dir_vid . $_SESSION['username']."_".$_POST['year'].".". $videoFileType;

        if($videoFileType != "mp4") {
            echo "Sorry, only MP4 files are allowed.";
            $uploadOk = 0;
        }
        else {
            $target_files[] = $newVideoName;
        }
    }

    var_dump($target_files);

    // Check if $uploadOk is set to 0 by an error
    if ($uploadOk == 0) {
        echo "Sorry, your file was not uploaded.";
    // if everything is ok, try to upload file
    } else {
        for($i=0; $i<sizeof($target_files); $i++){
            if (move_uploaded_file($_FILES['uploadedFiles']['tmp_name'][$i], $target_files[$i])) {
                echo "The file ". basename( $_FILES['uploadedFiles']['name'][$i]). " has been uploaded.";
            } else {
                echo "Sorry, there was an error uploading your file.";
            }
        }
    }
}
?>


<h1>Welcome <?php echo $_SESSION["username"]; ?>!</h1>

<h2>Data</h2>
<form action="" method="POST" enctype="multipart/form-data">
    <p><label>Select Year : </label>
    <select id="year" name="year">
        <?php 
            for($i=1901; $i<=2020; $i++){
                echo '<option value="'.$i.'">'.$i.'</option>';
            }
        ?>
    </select></p>
    <p><label>Height : </label>
    <input type="text" id="height" name="height" placeholder="Height" /></p>
    <p><label>Weight : </label>
    <input type="text" id="weight" name="weight" placeholder="Weight" /></p>
    <p><label>School : </label>
    <input type="text" id="school" name="school" placeholder="School" /></p>
    <p><label>Class : </label>
    <input type="text" id="class" name="class" placeholder="Class" /></p>
    <p><label>Choose picture : </label>
    <input type="file" id="picture" name="uploadedFiles[]" accept="image/jpeg, image/jpg" /></p>
    <p><label>Choose Audio : </label>
    <input type="file" id="audio" name="uploadedFiles[]" accept="audio/mp3" /></p>
    <p><label>Choose Video : </label>
    <input type="file" id="video" name="uploadedFiles[]" accept="video/mp4" /></p>

    <input type="submit" id="submit" name="submit" value="submit" /></p>
</form>


欢迎
资料
选择年份：

高度：

重量：

学校：

类别：

选择图片：

选择音频：

选择视频：



有关于它如何发生的信息吗？
对我来说很有用。！！我不知道为什么，但我面临上述所有情况。如果我同时上载所有文件，则不会导致任何问题！：（这很奇怪！它对我有效。！！我不知道为什么，但我面临上述所有情况。如果我同时上载所有文件，则不会导致任何问题！：（这很奇怪！