function getFileName(path){

    var pos1 = path.lastIndexOf('/');
    var pos2 = path.lastIndexOf('\\');
    var pos  = Math.max(pos1, pos2)
    if( pos<0 )
        return path;
    else
        return path.substring(pos+1);
}

2.不带后缀
getFileName(path) {

  var pos1 = path.lastIndexOf('/')
  var pos2 = path.lastIndexOf('\\')
  var pos = Math.max(pos1, pos2)
  if (pos < 0) {
    return path
  }
  else {
    let tempPath = path.substring(pos + 1);
    return tempPath.substring(0, tempPath.lastIndexOf("."));
  }
}