gistfile1.txt

# rescue la noi de xu ly ngoai le. 
# raise is phuong thuc giup chung ta dua ra ngoai le.  Dua ra ngoai le hien tai. Neu ko co thi bi loi RuntimeError
# retry: lap lai code o begin. 
# ensure tuong tu finally
# throw/catch : sau catch la 1 block. tiep tuc xu li khi gap throw thi vang ra ngoai tuong tu nhu break


begin
    file = open("file_name.txt")
   if file
      puts "File opened successfully"
   end
rescue
    puts "File not found"
    retry
end



def raise_and_rescue  
  begin  
    puts '1'  
    raise '2'  
    puts '3'  
  rescue  
    puts '4'  
  end  
  puts '5'  
end  
raise_and_rescue  

# Output

1
4
5 

catch (:done)  do
 // some code
    throw :done unless #$$%%
 //some code
end