js根据后缀判断文件文件类型

function getFileType(fileName) {
    // 后缀获取
    let suffix = '';
    // 获取类型结果
    let result = '';
    try {
      const flieArr = fileName.split('.');
      suffix = flieArr[flieArr.length - 1];
    } catch (err) {
      suffix = '';
    }
    // fileName无后缀返回 false
    if (!suffix) { return false; }
    suffix = suffix.toLocaleLowerCase();
    // 图片格式
    const imglist = ['png', 'jpg', 'jpeg', 'bmp', 'gif'];
    // 进行图片匹配
    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 excelist = ['xls', 'xlsx'];
    result = excelist.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 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';
  }