如何将文件上载限制为仅仅.xlxs和.docx文件

Question

I am working on a file upload functionality which should only allow .xlxs and .docx files. At the moment with the code below I am able to limit uploads to .xlsx only. I would however like to also upload .docx files but it seems my piece of code is preventing the .docx files from being uploaded.

 if (files.length > 0) {

      if (files[0].name.lastIndexOf('.docx') === -1 || files[0].name.lastIndexOf('.xlsx') === -1) {
         $.msgbox("Please note: only excel file formats are allowed. Please download the provided upload template, see the link below.");
         this.value = '';
         return;
      }

So that code above should spit out anything that is not xlsx or docx but the problem is it is spitting out docx as well

Answer 1

您可以在HTML代码中列出受限文件类型：

<input type="file" accept=".xlxs,.docx">

Answer 2

try your code like this:

if (files[0].name.lastIndexOf('.docx') === -1 && files[0].name.lastIndexOf('.xlsx') === -1) {
     $.msgbox("Please note: only excel file formats are allowed. Please download the provided upload template, see the link below.");
     this.value = '';
     return;
}

You're checking if it's not docx AND it's not xlsx, not OR