In Java How many overloaded add() and addAll() methods are available in the List interface? Describe the need and uses.
In Java, the List
interface, which is part of the Java Collections Framework, provides several overloaded methods for adding elements to a list. Specifically, the add()
and addAll()
methods are defined in the List
interface and its superinterfaces.
add()
MethodsThe add()
method is overloaded in the List
interface as follows:
boolean add(E e)
: This method appends the specified element to the end of the list.
E
(the type of elements in the list).true
if the list changed as a result of the call.void add(int index, E element)
: This method inserts the specified element at the specified position in the list.
index
(the position at which the element is to be inserted) and an element of type E
.addAll()
MethodsThe addAll()
method is also overloaded in the List
interface:
boolean addAll(Collection<? extends E> c)
: This method appends all of the elements in the specified collection to the end of the list.
E
.true
if the list changed as a result of the call.boolean addAll(int index, Collection<? extends E> c)
: This method inserts all of the elements in the specified collection into the list, starting at the specified position.
index
(the position at which to insert the elements) and a collection of elements of type E
.true
if the list changed as a result of the call.add()
Methodadd()
method is essential for adding single elements to a list. It provides flexibility in how elements can be added, either at the end of the list or at a specific index.addAll()
MethodaddAll()
method is useful for adding multiple elements to a list in a single operation. This is more efficient than adding elements one by one, especially when dealing with large collections.In summary, the List
interface provides two overloaded add()
methods and two overloaded addAll()
methods, allowing for flexible and efficient manipulation of list elements. These methods are fundamental for managing collections of data in Java applications.