private boolean isChar(int position,char ch){
  if (_len >= 0 && position >= _len) {
    return false;
  }
  return Character.toLowerCase(ch) == Character.toLowerCase(_working[position]);
}

private boolean isChar ( int position , char ch ) { if ( _len >= 0 && position >= _len ) { return false ; } return Character . toLowerCase ( ch ) == Character . toLowerCase ( _working [ position ] ) ; }
checks if character at specified position is equal to specified char .
