如何检查 $_FILE 是否在 php 中设置？

how to check if a $_FILE is set in php?

提问by Nicolas de Fontenay

I've created a form with 3 <input type="file"/>

我创建了一个包含 3 的表单 <input type="file"/>

I see that I get an array with array(name=>"").

我看到我得到了一个数组array(name=>"")。

So I check if ($_FILE["myfilename"]["name"]=="")instead.

所以我if ($_FILE["myfilename"]["name"]=="")改为检查。

This works but it seems rather unusual to me.

这有效，但对我来说似乎很不寻常。

I was wondering if there was a better way to check if a file input is set or not?

我想知道是否有更好的方法来检查是否设置了文件输入？

回答by Pekka

There is: is_uploaded_file(). When dealing with uploaded files, you should always use it (and its cousin move_uploaded_file()) for security reasons.

有：is_uploaded_file()。在处理上传的文件时，move_uploaded_file()出于安全原因，您应该始终使用它（及其表亲）。

回答by Shakti Singh

You can use emptyto check if a variable is blank or not but Pekka's solution is best in this way

您可以使用empty检查变量是否为空，但 Pekka 的解决方案最好以这种方式

if (empty($_FILES["myfilename"]["name"]))

If you are checking that if a variable is set you can use issetfunction

如果您正在检查是否设置了变量，则可以使用isset函数

回答by Ciaran McNulty

The best way, assuming you're using a recent PHP (4.2+), is to check that:

假设您使用的是最新的 PHP (4.2+)，最好的方法是检查：

$_FILE['myfilename']['error'] === UPLOAD_ERR_OK

If this is true the upload worked, you can see the list of other possible values here

如果这是真的上传成功，您可以在此处查看其他可能值的列表

回答by Osahady

You can try this:

你可以试试这个：

if($_FILES['myfilename']['size'] > 0 ) {

}
else{
       echo 'File is not uploaded . . .';
}

回答by Manish Negi

Try this:

尝试这个：

if($_FILES["uploadImg"]['name'][0] != ''){
    //echo 'file attached';
}else{
    //echo 'no file attached';
}

This works for me...

这对我有用...