How many parts do these cups have and are they dishwasher safe?

Most picks here are marketed as dishwasher-safe (top rack) and verified-purchase reviewers confirm it, but part count matters: simpler two- and three-piece designs (NUK learner cups, Tommee Tippee) draw the easiest-to-clean praise, while convertible straw/360 sets and weighted-straw cups get repeated complaints about fiddly lids and straws that trap residue.