Java: Collections Class

The java.util.Collections class contains static utility methods for manipulating collections.

Some useful Collections methods

Assume the following declarations have been made:

   List list; int i; Comparator comp; 
   Object key; Object obj; Collection coll;

Returns	Method	Action
Rearranging - Sorting, Shuffling, . . .
	`sort(list)`	Sorts `list`.
	`sort(list, comp)`	Sorts `list`.
	`shuffle(list)`	Puts the elements of `list` in random order.
	`reverse(list)`	Reverses the elements of `list`.
Searching
`i =`	`binarySearch(list, key)`	Searches in `list` for `key`. Returns index of element or negative value if not found. See Searching.
`i =`	`binarySearch(list, key, comp)`	Searches in `list` for `key` using Comparator comp. Returns index of element or negative value if not found. See Searching.
`obj =`	`max(coll)`	Returns maximum valued object in the Collection `coll`.
`obj =`	`max(coll, comp)`	Returns maximum valued object in the Collection `coll` using Comparator `comp`.
`obj =`	`min(coll)`	Returns minimum valued object in the Collection `coll`.
`obj =`	`min(coll, comp)`	Returns minimum valued object in the Collection `coll` using Comparator `comp`.

There are many more methods in Collections, but the above are a good start.