Ordered in Java

1. What is ordered: What order is added, what is the order of the output, which is called ordered

Ordered collection: List,treemap (this is sorted by binary tree, naturally sorted by key value)

		Ordered No	Allow elements to repeat no
< Span style= "FONT-FAMILY:SIMSUN; font-size:18px ">collection		no
< Span style= "FONT-FAMILY:SIMSUN; font-size:18px ">list		Yes	Yes
Set	Abstractset	Whether	Whether
	HashSet
	treeset	Yes (sorted by binary tree)
< Span style= "FONT-FAMILY:SIMSUN; font-size:18px ">map	Abstra Ctmap	no	use Key-value to map and store data, key must be unique, value can repeat
	HashMap
	TreeMap	Yes (sort by binary tree)

Ordered in Java