Java : LinkedList with Examples
LinkedList (Java SE 18 & JDK 18) API Examples.
You will find code examples on most LinkedList methods.
Summary
final var list = new LinkedList<String>();
System.out.println(list); // []
list.add("aaa");
list.add("bbb");
list.add("ccc");
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.get(0)); // aaa
System.out.println(list.get(1)); // bbb
System.out.println(list.get(2)); // ccc
final var list = new LinkedList<String>();
System.out.println(list); // []
list.add("xxx");
list.add("yyy");
list.add("zzz");
System.out.println(list); // [xxx, yyy, zzz]
System.out.println(list.removeFirst()); // xxx
System.out.println(list); // [yyy, zzz]
System.out.println(list.removeFirst()); // yyy
System.out.println(list); // [zzz]
System.out.println(list.removeFirst()); // zzz
System.out.println(list); // []
Fields declared in AbstractList
Constructors
LinkedList ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.add("aaa");
list.add("bbb");
list.add("ccc");
System.out.println(list); // [aaa, bbb, ccc]
LinkedList (Collection<? extends E> c)
final var c = List.of("aaa", "bbb", "ccc");
System.out.println(c); // [aaa, bbb, ccc]
final var list = new LinkedList<>(c);
System.out.println(list); // [aaa, bbb, ccc]
Methods
void add (int index, E element)
final var src = List.of("a", "b", "c");
System.out.println(src); // [a, b, c]
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
list.add(0, "A");
System.out.println(list); // [A, a, b, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
list.add(1, "B");
System.out.println(list); // [a, B, b, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
list.add(2, "C");
System.out.println(list); // [a, b, C, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
list.add(3, "D");
System.out.println(list); // [a, b, c, D]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
//list.add(4, "D"); // IndexOutOfBoundsException
}
boolean add (E e)
This method is equivalent to addLast(E e).
boolean addAll (int index, Collection<? extends E> c)
final var src = List.of("a", "b", "c");
System.out.println(src); // [a, b, c]
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
System.out.println(list.addAll(0, List.of("A1", "A2"))); // true
System.out.println(list); // [A1, A2, a, b, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
System.out.println(list.addAll(1, List.of("B1", "B2", "B3"))); // true
System.out.println(list); // [a, B1, B2, B3, b, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
System.out.println(list.addAll(2, List.of("C1", "C2", "C3", "C4"))); // true
System.out.println(list); // [a, b, C1, C2, C3, C4, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
System.out.println(list.addAll(3, List.of())); // false
System.out.println(list); // [a, b, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
//list.addAll(4, List.of("E")); // IndexOutOfBoundsException
}
final var src = List.of("a", "b", "c");
System.out.println(src);// [a, b, c]
final var list = new LinkedList<>(src);
System.out.println(list.addAll(3, Set.of("D1", "D2", "D3"))); // true
System.out.println(list); // [a, b, c, D3, D2, D1]
boolean addAll (Collection<? extends E> c)
final var list = new LinkedList<String>();
System.out.println(list.addAll(List.of("a1"))); // true
System.out.println(list); // [a1]
System.out.println(list.addAll(List.of("b1", "b2"))); // true
System.out.println(list); // [a1, b1, b2]
System.out.println(list.addAll(List.of("c1", "c2", "c3"))); // true
System.out.println(list); // [a1, b1, b2, c1, c2, c3]
System.out.println(list.addAll(List.of())); // false
System.out.println(list); // [a1, b1, b2, c1, c2, c3]
final var list = new LinkedList<String>();
System.out.println(list); // []
System.out.println(list.addAll(Set.of("c1", "c2", "c3"))); // true
System.out.println(list); // [c3, c2, c1]
void addFirst (E e)
final var list = new LinkedList<String>();
System.out.println(list); // []
list.addFirst("aaa");
System.out.println(list); // [aaa]
list.addFirst("bbb");
System.out.println(list); // [bbb, aaa]
list.addFirst("ccc");
System.out.println(list); // [ccc, bbb, aaa]
void addLast (E e)
final var list = new LinkedList<String>();
System.out.println(list); // []
list.addLast("aaa");
System.out.println(list); // [aaa]
list.addLast("bbb");
System.out.println(list); // [aaa, bbb]
list.addLast("ccc");
System.out.println(list); // [aaa, bbb, ccc]
void clear ()
final var list = new LinkedList<String>();
list.add("a");
list.add("b");
list.add("c");
System.out.println(list); // [a, b, c]
list.clear();
System.out.println(list); // []
Object clone ()
final var list = new LinkedList<String>();
list.add("a");
list.add("b");
list.add("c");
System.out.println(list); // [a, b, c]
final var cloned = list.clone();
System.out.println(cloned); // [a, b, c]
System.out.println(cloned.getClass()); // class java.util.LinkedList
boolean contains (Object o)
final var list = new LinkedList<String>();
Collections.addAll(list, "a", "b", "c");
System.out.println(list); // [a, b, c]
System.out.println(list.contains("")); // false
System.out.println(list.contains("a")); // true
System.out.println(list.contains("b")); // true
System.out.println(list.contains("c")); // true
System.out.println(list.contains("abc")); // false
Iterator<E> descendingIterator ()
final var list = new LinkedList<>(List.of("aaa", "bbb", "ccc"));
System.out.println(list); // [aaa, bbb, ccc]
final var iterator = list.descendingIterator();
System.out.println("-- forEachRemaining --");
iterator.forEachRemaining(System.out::println);
// Result
// ↓
//-- forEachRemaining --
//ccc
//bbb
//aaa
E element ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.addLast("aaa");
list.addLast("bbb");
list.addLast("ccc");
System.out.println(list.element()); // aaa
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.removeFirst()); // aaa
System.out.println(list); // [bbb, ccc]
System.out.println(list.element()); // bbb
System.out.println(list); // [bbb, ccc]
System.out.println(list.removeFirst()); // bbb
System.out.println(list); // [ccc]
System.out.println(list.element()); // ccc
System.out.println(list); // [ccc]
System.out.println(list.removeFirst()); // ccc
System.out.println(list); // []
try {
list.element();
} catch (NoSuchElementException e) {
System.out.println(e);
}
// Result
// ↓
//java.util.NoSuchElementException
E get (int index)
final var list = new LinkedList<String>();
Collections.addAll(list, "a", "b", "c");
System.out.println(list); // [a, b, c]
//list.get(-1); // IndexOutOfBoundsException
System.out.println(list.get(0)); // a
System.out.println(list.get(1)); // b
System.out.println(list.get(2)); // c
//list.get(3); // IndexOutOfBoundsException
final var list = new LinkedList<Integer>();
Collections.addAll(list, 10, 20, 30, 40);
System.out.println(list); // [10, 20, 30, 40]
System.out.println(list.get(0)); // 10
System.out.println(list.get(1)); // 20
System.out.println(list.get(2)); // 30
System.out.println(list.get(3)); // 40
E getFirst ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.addLast("aaa");
list.addLast("bbb");
list.addLast("ccc");
System.out.println(list.getFirst()); // aaa
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.removeFirst()); // aaa
System.out.println(list); // [bbb, ccc]
System.out.println(list.getFirst()); // bbb
System.out.println(list); // [bbb, ccc]
System.out.println(list.removeFirst()); // bbb
System.out.println(list); // [ccc]
System.out.println(list.getFirst()); // ccc
System.out.println(list); // [ccc]
System.out.println(list.removeFirst()); // ccc
System.out.println(list); // []
try {
list.getFirst();
} catch (NoSuchElementException e) {
System.out.println(e);
}
// Result
// ↓
//java.util.NoSuchElementException
E getLast ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.addLast("aaa");
list.addLast("bbb");
list.addLast("ccc");
System.out.println(list.getLast()); // ccc
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.removeLast()); // ccc
System.out.println(list); // [aaa, bbb]
System.out.println(list.getLast()); // bbb
System.out.println(list); // [aaa, bbb]
System.out.println(list.removeLast()); // bbb
System.out.println(list); // [aaa]
System.out.println(list.getLast()); // aaa
System.out.println(list); // [aaa]
System.out.println(list.removeLast()); // aaa
System.out.println(list); // []
try {
list.getLast();
} catch (NoSuchElementException e) {
System.out.println(e);
}
// Result
// ↓
//java.util.NoSuchElementException
int indexOf (Object o)
final var list = new LinkedList<String>();
Collections.addAll(list, "a", "b", "c", "a", "b", "c");
System.out.println(list); // [a, b, c, a, b, c]
System.out.println(list.indexOf("")); // -1
System.out.println(list.indexOf("a")); // 0
System.out.println(list.indexOf("b")); // 1
System.out.println(list.indexOf("c")); // 2
System.out.println(list.indexOf("d")); // -1
System.out.println(list.indexOf("abc")); // -1
int lastIndexOf (Object o)
final var list = new LinkedList<String>();
Collections.addAll(list, "a", "b", "c", "a", "b", "c");
System.out.println(list); // [a, b, c, a, b, c]
System.out.println(list.lastIndexOf("")); // -1
System.out.println(list.lastIndexOf("a")); // 3
System.out.println(list.lastIndexOf("b")); // 4
System.out.println(list.lastIndexOf("c")); // 5
System.out.println(list.lastIndexOf("d")); // -1
System.out.println(list.lastIndexOf("abc")); // -1
ListIterator<E> listIterator (int index)
final var list = new LinkedList<String>();
Collections.addAll(list, "aaa", "bbb", "ccc");
System.out.println(list); // [aaa, bbb, ccc]
{
final var ret = list.listIterator(0);
ret.forEachRemaining(System.out::println);
// Result
// ↓
//aaa
//bbb
//ccc
}
{
final var ret = list.listIterator(1);
ret.forEachRemaining(System.out::println);
// Result
// ↓
//bbb
//ccc
}
{
final var ret = list.listIterator(2);
ret.forEachRemaining(System.out::println);
// Result
// ↓
//ccc
}
boolean offer (E e)
final var list = new LinkedList<String>();
System.out.println(list); // []
System.out.println(list.offer("aaa")); // true
System.out.println(list); // [aaa]
System.out.println(list.offer("bbb")); // true
System.out.println(list); // [aaa, bbb]
System.out.println(list.offer("ccc")); // true
System.out.println(list); // [aaa, bbb, ccc]
boolean offerFirst (E e)
final var list = new LinkedList<String>();
System.out.println(list); // []
System.out.println(list.offerFirst("aaa")); // true
System.out.println(list); // [aaa]
System.out.println(list.offerFirst("bbb")); // true
System.out.println(list); // [bbb, aaa]
System.out.println(list.offerFirst("ccc")); // true
System.out.println(list); // [ccc, bbb, aaa]
boolean offerLast (E e)
final var list = new LinkedList<String>();
System.out.println(list); // []
System.out.println(list.offerLast("aaa")); // true
System.out.println(list); // [aaa]
System.out.println(list.offerLast("bbb")); // true
System.out.println(list); // [aaa, bbb]
System.out.println(list.offerLast("ccc")); // true
System.out.println(list); // [aaa, bbb, ccc]
E peek ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.addLast("aaa");
list.addLast("bbb");
list.addLast("ccc");
System.out.println(list.peek()); // aaa
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.pollFirst()); // aaa
System.out.println(list); // [bbb, ccc]
System.out.println(list.peek()); // bbb
System.out.println(list); // [bbb, ccc]
System.out.println(list.pollFirst()); // bbb
System.out.println(list); // [ccc]
System.out.println(list.peek()); // ccc
System.out.println(list); // [ccc]
System.out.println(list.pollFirst()); // ccc
System.out.println(list); // []
System.out.println(list.peek()); // null
System.out.println(list); // []
E peekFirst ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.addLast("aaa");
list.addLast("bbb");
list.addLast("ccc");
System.out.println(list.peekFirst()); // aaa
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.pollFirst()); // aaa
System.out.println(list); // [bbb, ccc]
System.out.println(list.peekFirst()); // bbb
System.out.println(list); // [bbb, ccc]
System.out.println(list.pollFirst()); // bbb
System.out.println(list); // [ccc]
System.out.println(list.peekFirst()); // ccc
System.out.println(list); // [ccc]
System.out.println(list.pollFirst()); // ccc
System.out.println(list); // []
System.out.println(list.peekFirst()); // null
System.out.println(list); // []
E peekLast ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.addLast("aaa");
list.addLast("bbb");
list.addLast("ccc");
System.out.println(list.peekLast()); // ccc
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.pollLast()); // ccc
System.out.println(list); // [aaa, bbb]
System.out.println(list.peekLast()); // bbb
System.out.println(list); // [aaa, bbb]
System.out.println(list.pollLast()); // bbb
System.out.println(list); // [aaa]
System.out.println(list.peekLast()); // aaa
System.out.println(list); // [aaa]
System.out.println(list.pollLast()); // aaa
System.out.println(list); // []
System.out.println(list.peekLast()); // null
System.out.println(list); // []
E poll ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.add("aaa");
list.add("bbb");
list.add("ccc");
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.poll()); // aaa
System.out.println(list); // [bbb, ccc]
System.out.println(list.poll()); // bbb
System.out.println(list); // [ccc]
System.out.println(list.poll()); // ccc
System.out.println(list); // []
System.out.println(list.poll()); // null
System.out.println(list); // []
E pollFirst ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.add("aaa");
list.add("bbb");
list.add("ccc");
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.pollFirst()); // aaa
System.out.println(list); // [bbb, ccc]
System.out.println(list.pollFirst()); // bbb
System.out.println(list); // [ccc]
System.out.println(list.pollFirst()); // ccc
System.out.println(list); // []
System.out.println(list.pollFirst()); // null
System.out.println(list); // []
E pollLast ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.add("aaa");
list.add("bbb");
list.add("ccc");
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.pollLast()); // ccc
System.out.println(list); // [aaa, bbb]
System.out.println(list.pollLast()); // bbb
System.out.println(list); // [aaa]
System.out.println(list.pollLast()); // aaa
System.out.println(list); // []
System.out.println(list.pollLast()); // null
System.out.println(list); // []
E pop ()
This method is equivalent to removeFirst().
void push (E e)
This method is equivalent to addFirst(E e).
E remove ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.add("aaa");
list.add("bbb");
list.add("ccc");
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.remove()); // aaa
System.out.println(list); // [bbb, ccc]
System.out.println(list.remove()); // bbb
System.out.println(list); // [ccc]
System.out.println(list.remove()); // ccc
System.out.println(list); // []
try {
list.remove();
} catch (NoSuchElementException e) {
System.out.println(e);
}
// Result
// ↓
//java.util.NoSuchElementException
E remove (int index)
final var src = List.of("a", "b", "c");
System.out.println(src); // [a, b, c]
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
System.out.println(list.remove(0)); // a
System.out.println(list); // [b, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
System.out.println(list.remove(1)); // b
System.out.println(list); // [a, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
System.out.println(list.remove(2)); // c
System.out.println(list); // [a, b]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
//list.remove(3); // IndexOutOfBoundsException
}
boolean remove (Object o)
final var src = List.of("a", "b", "a", "b", "A", "B");
System.out.println(src); // [a, b, a, b, A, B]
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, a, b, A, B]
System.out.println(list.remove("")); // false
System.out.println(list); // [a, b, a, b, A, B]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, a, b, A, B]
System.out.println(list.remove("a")); // true
System.out.println(list); // [b, a, b, A, B]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, a, b, A, B]
System.out.println(list.remove("b")); // true
System.out.println(list); // [a, a, b, A, B]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, a, b, A, B]
System.out.println(list.remove("A")); // true
System.out.println(list); // [a, b, a, b, B]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, a, b, A, B]
System.out.println(list.remove("B")); // true
System.out.println(list); // [a, b, a, b, A]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, a, b, A, B]
System.out.println(list.remove("C")); // false
System.out.println(list); // [a, b, a, b, A, B]
}
E removeFirst ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.add("aaa");
list.add("bbb");
list.add("ccc");
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.removeFirst()); // aaa
System.out.println(list); // [bbb, ccc]
System.out.println(list.removeFirst()); // bbb
System.out.println(list); // [ccc]
System.out.println(list.removeFirst()); // ccc
System.out.println(list); // []
try {
list.removeFirst();
} catch (NoSuchElementException e) {
System.out.println(e);
}
// Result
// ↓
//java.util.NoSuchElementException
boolean removeFirstOccurrence (Object o)
final var list = new LinkedList<>(List.of("aaa", "BBB", "aaa", "BBB", "ccc"));
System.out.println(list); // [aaa, BBB, aaa, BBB, ccc]
System.out.println(list.removeFirstOccurrence("aaa")); // true
System.out.println(list); // [BBB, aaa, BBB, ccc]
System.out.println(list.removeFirstOccurrence("BBB")); // true
System.out.println(list); // [aaa, BBB, ccc]
System.out.println(list.removeFirstOccurrence("XXX")); // false
System.out.println(list); // [aaa, BBB, ccc]
E removeLast ()
final var list = new LinkedList<String>();
System.out.println(list); // []
list.add("aaa");
list.add("bbb");
list.add("ccc");
System.out.println(list); // [aaa, bbb, ccc]
System.out.println(list.removeLast()); // ccc
System.out.println(list); // [aaa, bbb]
System.out.println(list.removeLast()); // bbb
System.out.println(list); // [aaa]
System.out.println(list.removeLast()); // aaa
System.out.println(list); // []
try {
list.removeLast();
} catch (NoSuchElementException e) {
System.out.println(e);
}
// Result
// ↓
//java.util.NoSuchElementException
boolean removeLastOccurrence (Object o)
final var list = new LinkedList<>(List.of("aaa", "BBB", "aaa", "BBB", "ccc"));
System.out.println(list); // [aaa, BBB, aaa, BBB, ccc]
System.out.println(list.removeLastOccurrence("BBB")); // true
System.out.println(list); // [aaa, BBB, aaa, ccc]
System.out.println(list.removeLastOccurrence("aaa")); // true
System.out.println(list); // [aaa, BBB, ccc]
System.out.println(list.removeLastOccurrence("XXX")); // false
System.out.println(list); // [aaa, BBB, ccc]
E set (int index, E element)
final var src = List.of("a", "b", "c");
System.out.println(src); // [a, b, c]
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
System.out.println(list.set(0, "A")); // a
System.out.println(list); // [A, b, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
System.out.println(list.set(1, "B")); // b
System.out.println(list); // [a, B, c]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
System.out.println(list.set(2, "C")); // c
System.out.println(list); // [a, b, C]
}
{
final var list = new LinkedList<>(src);
System.out.println(list); // [a, b, c]
//list.set(3, "D"); // IndexOutOfBoundsException
}
int size ()
final var list = new LinkedList<String>();
System.out.println(list); // []
System.out.println(list.size()); // 0
list.add("a");
System.out.println(list); // [a]
System.out.println(list.size()); // 1
list.add("b");
list.add("c");
list.add("d");
System.out.println(list); // [a, b, c, d]
System.out.println(list.size()); // 4
Spliterator<E> spliterator ()
final var list = new LinkedList<String>();
Collections.addAll(list, "aaa", "bbb", "ccc");
System.out.println(list); // [aaa, bbb, ccc]
final var spliterator = list.spliterator();
spliterator.forEachRemaining(System.out::println);
// Result
// ↓
//aaa
//bbb
//ccc
Object[] toArray ()
final var list = new LinkedList<String>();
Collections.addAll(list, "a", "b", "c");
System.out.println(list); // [a, b, c]
final Object[] array = list.toArray();
System.out.println(Arrays.toString(array)); // [a, b, c]
<T> T[] toArray (T[] a)
final var list = new LinkedList<String>();
Collections.addAll(list, "a", "b", "c");
System.out.println(list); // [a, b, c]
final String[] array = list.toArray(new String[0]);
System.out.println(Arrays.toString(array)); // [a, b, c]
final var list = new LinkedList<String>();
Collections.addAll(list, "a", "b", "c");
System.out.println(list); // [a, b, c]
{
final String[] array = new String[3];
System.out.println(Arrays.toString(array)); // [null, null, null]
final var ret = list.toArray(array);
System.out.println(Arrays.toString(array)); // [a, b, c]
System.out.println(Arrays.toString(ret)); // [a, b, c]
}
{
final String[] array = new String[5];
System.out.println(Arrays.toString(array)); // [null, null, null, null, null]
final var ret = list.toArray(array);
System.out.println(Arrays.toString(array)); // [a, b, c, null, null]
System.out.println(Arrays.toString(ret)); // [a, b, c, null, null]
}
{
final String[] array = new String[1];
System.out.println(Arrays.toString(array)); // [null]
final var ret = list.toArray(array);
System.out.println(Arrays.toString(array)); // [null]
System.out.println(Arrays.toString(ret)); // [a, b, c]
}
Methods declared in AbstractSequentialList
Methods declared in AbstractList
equals, hashCode, listIterator, removeRange, subList
Please see the link below.
Methods declared in AbstractCollection
containsAll, isEmpty, removeAll, retainAll, toString
Please see the link below.
Methods declared in Collection
Methods declared in Deque
Methods declared in Iterable
Methods declared in List
containsAll, equals, hashCode, isEmpty, iterator, listIterator, removeAll, replaceAll, retainAll, sort, subList
Please see the link below.
Related posts
- API Examples