When you do a quick format or full format, the data is not actually delete from the hard drive. Instead, the index to all the data is deleted, and all the sectors on the hard drive are marked to be overridden; including the sector where the files you want to recover are located in. At this point if you did not save any files to the hard drive you formatted, then you should technically be able to recover all of the files using a recovery program like Recuva.
https://www.piriform.com/recuva
If you have saved new files to the hard drive, then it is possible some of those sectors that contains data of the files you want to recover have been overridden. That makes recovering the "old" files more difficult and you may need to have it...