检查特定的输入文件是否为空 [英] Check if specific input file is empty

问题描述

在我的表单中，我有3个用于文件上传的输入字段:

In my form I have 3 input fields for file upload:

<input type=file name="cover_image">
<input type=file name="image1">
<input type=file name="image2">

如何检查cover_image是否为空-没有文件可上传?

How can I check if cover_image is empty - no file is put for upload?

推荐答案

您可以使用$_FILES数组上的size字段进行检查，如下所示:

You can check by using the size field on the $_FILES array like so:

if ($_FILES['cover_image']['size'] == 0 && $_FILES['cover_image']['error'] == 0)
{
    // cover_image is empty (and not an error)
}

(我也在这里检查error，因为如果出现问题可能是0.我不会使用name进行此检查，因为这可以被覆盖)

(I also check error here because it may be 0 if something went wrong. I wouldn't use name for this check since that can be overridden)

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