I wish to sell my iphone 5, should i worry about data recovery after i format it?

I want to get a S3 and wish to sell my phone, should i worry about messages, contacts, email and notes information being recovered? I'm going to format it using the settings within the phone itself.
i used this phone a lot in bank information and my job's email. Don't want any information obtained. Should i just format and sell it? Or better just keep the phone or destroy it?

You should be fine formatting it. Just factory reset it from the phone, and then plug it in and do a OS recovery in iTunes.

iPhones rely on FLASH memory to store data, meaning once it is gone, it is gone. You do not have to worry about it.

Computers, because they use traditional spinning disk hard drives, need to be rewrote over to completely erase data(even if said data is "deleted")

iPhones and other phones utilize flash data, and once you delete or format the phone, all information is gone.

Visit glyde.com/wipe for easy instructions on how to restore the iPhone 5 to its factory settings. You can also sell the phone on glyde.com. IPhone 5 are getting as much as $600 currently.

There's nothing to worry. Just format the device. I will do the work. Still if you want to avoid any Risk, then follow -
1. Format it.
2. Fill it again with waste stuff.
3. Reformat it.

It will remove all chances of data recovery.

No need to keep the phone and destroy it! Re-format it, go to Apple's website if you're at all confused about wiping data from the phone.

little video about it: