Do I need transformer for my MacBook/iPhone?

Hello!
I tried my best to search older posts about this subject (also googled many times) but I still can't find a clear answer.
I'm coming to Japan (Osaka) and I will take my Macbook Air and iPhone 4S with me. I already bought a world wide adapter but do I also need a transformer? My electronics are using higher European voltage (220-240 V and 50 Hz) and I found out from Apple's website that MacBooks are suitable for 100-240 V and 50-60 Hz so does that mean that I won't have problems of charging my laptop? But what about my iPhone? Couldn't find its voltage coverage.

And if I need a transformer, am I able to buy one from an airport (Kansai International airport)?

Thank you! :)

All you will need are your usual charging cables & the adapter as the Mac and indeed all laptops that I know of are rated for 100v-240v (typing this on a european Samsung laptop from a hotel in Tokyo)The iphone will also be fine. If by any chance you need an additional adaptor to fit Japanese sockets they are freely available & cheap in Akihabara.

Sorry, just noticed you are going to Osaka. For Akihabara read Den Den Town :)

If you are looking for voltage ratings on the devices, you will not find them. Voltage rating is not a property of the devices themselves but of the power supplies (the boxy things that go between the wall and the devices), so that's where you should look.

Thank you very much for your answers! I was really worried if I would break my devices, haha. :)