How to Recover Files from Formatted USB Flash Drive

You may format USB flash drive due to various reasons, such as formatting flash drive by mistake or the USB flash drive shows not formatted error.
Users Need to Unformat USB Flash Drive

User1: I formatted my SanDisk 32 GB USB Flash drive, but I don’t know that my brother used my flash drive to backup some important files on his computer. When he told me, the USB flash drive has been formatted. So is there any method that can help me restore the files lost due to formatting? Those lost files include some pictures, videos and music. I need detailed information. Thanks for any help!