How to remove saves from singleplayer minecraft world?

I went into a 1.8 world while using 1.7.9 and everything in my chests was gone. In panic, I wuit and went back in with 1.8, but EVERYTHING in my chests were gone. Diamonds, armour, gold, EVERYTHING. Is there anyway to reomove the save from when i logged in with 1.7.9 and everything disappeared?

Yes if you made a world backup before the stuff got deleted. If you didn't make a world backup then, no unfortunately. You should start making them, its fairly easy to do, just Google or YouTube a tutorial.