What should a parent do to a toddler who always screams or cries if he doesnt get what he wants?

So one time me and my son went grocery shopping..he saw this toy and wanted it pretty bad that he threw a fit and he laid on the floor.I looked at him and calmy said if you dont behave were going home.I turned my back on him and started walking away and going outside the building.He stopped crying and started following me behind.We ended going home and not doing grocery but after that incident,he never did that scene again.