如何用JavaScript检测标签错误的WebP文件？[副本]

Question

我接受这样的新文件：

<input type="file" accept="image/x-png,image/gif,image/jpeg" required>

Answer 1

//JS

    <script>
      var fileextension = "jpg|jpeg|gif|png|ico|bmp";

      function checkExtension(value)
      {
      if(value=="")return true;
      var re = new RegExp("^.+\.("+fileextension+")$","i");
      if(!re.test(value))
      {
      alert("File not allowed! \n" + value + "\n\nAllowed:    
      "+fileextension.replace(/\|/g,',')+" \n\n");
       return false;
       }

       return true;
       }
   </script>

//html

 <input type="file" name="image" onChange="checkExtension(this.value)">