I'm making a 2D platformer game and to represent a level I'm using 2D array of tiles which are classes with fields for position, type and various flags. When I change the class key word in the tile class to struct, a loaded map consumes about 20% less memory.
I don't know about rights and wrongs of this action, I just want to know why the difference in memory consumption.
Edit: numbers are 1038 MB with tiles as classes and 845 MB as structs (without most of game data).