List also provides a richer iterator, called a ListIterator, which allows you to traverse the list in either direction, modify the list during iteration, and obtain the current position of the iterator. Here's a little method to swap two indexed values in a List.Īs you'd expect, the Iterator returned by List's iterator operation returns the elements of the list in proper sequence. This call is the positional access analog of Collection's addAll operation. The elements are inserted in the order they are returned by the specified Collection's iterator. The addAll operation inserts all the elements of the specified Collection starting at the specified position. The first or last index of the specified element in the list. (The set and remove operations return the old value that is being overwritten or removed.) Other operations ( indexOf and lastIndexOf) return The basic positional access operations are get, set, add and remove.

Two List objects are equal if they contain the same elements in the same order. Set interface, List strengthens the requirements on the equals and hashCode methods so that two List objects can be compared for logical equality without regard to their implementation classes. Thus, the following idiom concatenates one list to another.

The add and addAll operations always append the new element(s) to the end of the list. The remove operation always removes the first occurrence of the specified element from the list. If you're not familiar with them from Collection, now would be a good time to read The operations inherited from Collection all do about what you'd expect them to do, assuming you're already familiar with them. LinkedList which offers better performance under certain circumstances. The Java platform contains two general-purpose List implementations.ĪrrayList, which is usually the better-performing implementation, and Range-view The sublist method performs arbitrary range operations on the list.ListIterator methods provide this behavior.

Iteration extends Iterator semantics to take advantage of the list's sequential nature.

Search searches for a specified object in the list and returns its numerical position.

Positional access manipulates elements based on their numerical position in the list.

In addition to the operations inherited from Collection, the List interface includes operations for the following: Collection (sometimes called a sequence).

Collection in java tutorial