The List interface extends Collection and declares the behavior of a collection that stores a sequence of elements. Elements can be inserted or accessed by their position in the list, using a zero-based index. A list may contain duplicate elements. List is a generic interface that has this declaration:
interface List<E>
Here, E specifies the type of objects that the list will hold
Table of List interface
| Method | Description | ||
| boolean add(E obj) | Adds obj to the invoking collection. Returns true if obj was added | ||
| to the collection. Returns false if obj is already a member of the | |||
| collection and the collection does not allow duplicates. | |||
| boolean addAll(Collection<? extends E> c) | Adds all the elements of c to the invoking collection. Returns true | ||
| if the operation succeeded (i.e., the elements were added). | |||
| Otherwise, returns false. | |||
| void clear( ) | Removes all elements from the invoking collection. | ||
| boolean contains(Object obj) | Returns true if obj is an element of the invoking collection. | ||
| Otherwise, returns false. | |||
| boolean containsAll(Collection<?> c) | Returns true if the invoking collection contains all elements | ||
| of c. Otherwise, returns false. | |||
| boolean equals(Object obj) | Returns true if the invoking collection and obj are equal. | ||
| Otherwise, returns false. | |||
| int hashCode( ) | Returns the hash code for the invoking collection. | ||
| boolean isEmpty( ) | Returns true if the invoking collection is empty. Otherwise, | ||
| returns false. | |||
| Iterator<E> iterator( ) | Returns an iterator for the invoking collection. | ||
| boolean remove(Object obj) | Removes one instance of obj from the invoking collection. Returns | ||
| true if the element was removed. Otherwise, returns false. | |||
| boolean removeAll(Collection<?> c) | Removes all elements of c from the invoking collection. Returns | ||
| true if the collection changed (i.e., elements were removed). | |||
| Otherwise, returns false. | |||
| boolean retainAll(Collection<?> c) | Removes all elements from the invoking collection except those | ||
| in c. Returns true if the collection changed (i.e., elements were | |||
| removed). Otherwise, returns false. | |||
| int size( ) | Returns the number of elements held in the invoking collection. | ||
| Object[ ] toArray( ) | Returns an array that contains all the elements stored in the | ||
| invoking collection. The array elements are copies of the | |||
| collection elements. | |||
| <T> T[ ] toArray(T array[ ]) | Returns an array that contains the elements of the invoking | ||
| collection. The array elements are copies of the collection | |||
| elements. If the size of array equals the number of elements, | |||
| these are returned in array. If the size of array is less than the | |||
| number of elements, a new array of the necessary size is allocated | |||
| and returned. If the size of array is greater than the number of | |||
| elements, the array element following the last collection element | |||
| is set to null. An ArrayStoreException is thrown if any collection | |||
| element has a type that is not a subtype of array. | |||
| Method | Description | ||
| void add(int index, E obj) | Inserts obj into the invoking list at the index passed in index. | ||
| Any preexisting elements at or beyond the point of insertion | |||
| are shifted up. Thus, no elements are overwritten. | |||
| boolean addAll(int index, | Inserts all elements of c into the invoking list at the index | ||
| Collection<? extends E> c) | passed in index. Any preexisting elements at or beyond the | ||
| point of insertion are shifted up. Thus, no elements are | |||
| overwritten. Returns true if the invoking list changes and | |||
| returns false otherwise. | |||
| E get(int index) | Returns the object stored at the specified index within the | ||
| invoking collection. | |||
| int indexOf(Object obj) | Returns the index of the first instance of obj in the invoking | ||
| list. If obj is not an element of the list, –1 is returned. | |||
| int lastIndexOf(Object obj) | Returns the index of the last instance of obj in the invoking | ||
| list. If obj is not an element of the list, –1 is returned. | |||
| ListIterator<E> listIterator( ) | Returns an iterator to the start of the invoking list. | ||
| ListIterator<E> listIterator(int index) | Returns an iterator to the invoking list that begins at the | ||
| specified index. | |||
| E remove(int index) | Removes the element at position index from the invoking list | ||
| and returns the deleted element. The resulting list is compacted. | |||
| That is, the indexes of subsequent elements are decremented | |||
| by one. | |||
| E set(int index, E obj) | Assigns obj to the location specified by index within the | ||
| invoking list. | |||
| List<E> subList(int start, int end) | Returns a list that includes elements from start to end–1 in the | ||
| invoking list. Elements in the returned list are also referenced | |||
| by the invoking object. |