如何检查文件字段是否为空？

Question

我很难用 $_FILES

我想检查它是否为空,如果它不是空的,那么它不应该尝试上传文件.我该如何检查？

Answer 1

if($_FILES["file"]["error"] != 0) {
//stands for any kind of errors happen during the uploading
} 

还有

if($_FILES["file"]["error"] == 4) {
//means there is no file uploaded
}

Answer 2

这应该工作

if ( ! empty($_FILES)) {...}

Answer 3

其他答案对我不起作用.所以我发布我的解决方案:

if($_FILES['theFile']['name']=='')
{
    //No file selected
}

Answer 4

这对我有用:

if ($_FILES['theFile']['tmp_name']!='') {
    // do this, upload file
} // if no file selected to upload, file isn't uploaded.

Answer 5

您可以使用UPLOAD_ERR_NO_FILE值:

function isset_file($file) {
    return (isset($file) && $file['error'] != UPLOAD_ERR_NO_FILE);
}

if(isset_file($_FILES['input_name'])) {
    // It's not empty
}

更新:由于发送$ _FILES ['input_name']可能会发出通知

function isset_file($name) {
    return (isset($_FILES[$name]) && $_FILES[$name]['error'] != UPLOAD_ERR_NO_FILE);
}

if(isset_file('input_name')) {
    // It's not empty
}