根据后缀判断文件类型

getFileType(fileName) {
      let suffix = ''; // 后缀获取
      let result = ''; // 获取类型结果
      if (fileName) {
        const flieArr = fileName.split('.'); // 根据.分割数组
        suffix = flieArr[flieArr.length - 1]; // 取最后一个
      }
      if (!suffix) return false; // fileName无后缀返回false
      suffix = suffix.toLocaleLowerCase(); // 将后缀所有字母改为小写方便操作
      // 匹配图片
      const imgList = ['png', 'jpg', 'jpeg', 'bmp', 'gif']; // 图片格式
      result = imgList.find(item => item === suffix);
      if (result) return 'image';
      // 匹配txt
      const txtList = ['txt'];
      result = txtList.find(item => item === suffix);
      if (result) return 'txt';
      // 匹配excel
      const excelList = ['xls', 'xlsx'];
      result = excelList.find(item => item === suffix);
      if (result) return 'excel';
      // 匹配word
      const wordList = ['doc', 'docx'];
      result = wordList.find(item => item === suffix);
      if (result) return 'word';
      // 匹配pdf
      const pdfList = ['pdf'];
      result = pdfList.find(item => item === suffix);
      if (result) return 'pdf';
      // 匹配ppt
      const pptList = ['ppt', 'pptx'];
      result = pptList.find(item => item === suffix);
      if (result) return 'ppt';
      // 匹配zip
      const zipList = ['rar', 'zip', '7z'];
      result = zipList.find(item => item === suffix);
      if (result) return 'zip';
      // 匹配视频
      const videoList = ['mp4', 'm2v', 'mkv', 'rmvb', 'wmv', 'avi', 'flv', 'mov', 'm4v'];
      result = videoList.find(item => item === suffix);
      if (result) return 'video';
      // 匹配音频
      const radioList = ['mp3', 'wav', 'wmv'];
      result = radioList.find(item => item === suffix);
      if (result) return 'radio';
      // 其他文件类型
      return 'other';
}