LinkedList

General

LinkedList is a built-in collection class in Ysharp that implements a singly linked list. It provides efficient insertion and removal at both ends, making it well suited for queue and stack style operations.

Note
Unlike Array, LinkedList does not provide constant-time random access. Accessing or modifying an element by index requires traversing the list from the head.

var list = new LinkedList();

Creates a new, empty LinkedList instance.

Reference

Instance methods

Method	Signature	Return Type	Description
`addFirst`	`list.addFirst(value)`	`null`	Inserts a value at the beginning of the list
`addLast`	`list.addLast(value)`	`null`	Inserts a value at the end of the list
`removeFirst`	`list.removeFirst()`	`any`	Removes and returns the first element
`removeLast`	`list.removeLast()`	`any`	Removes and returns the last element
`peekFirst`	`list.peekFirst()`	`any\|null`	Returns the first element without removing it
`peekLast`	`list.peekLast()`	`any\|null`	Returns the last element without removing it
`get`	`list.get(index : int)`	`any`	Returns the element at the given index
`set`	`list.set(index : int, value)`	`null`	Replaces the element at the given index
`contains`	`list.contains(value)`	`bool`	Returns true if the list contains the given value
`indexOf`	`list.indexOf(value)`	`int`	Returns the index of the first occurrence, or -1
`size`	`list.size()`	`int`	Returns the number of elements in the list
`isEmpty`	`list.isEmpty()`	`bool`	Returns true if the list contains no elements
`clear`	`list.clear()`	`null`	Removes all elements from the list
`toArray`	`list.toArray()`	`Array`	Returns a new Array containing all elements in order
`clone`	`list.clone()`	`LinkedList`	Returns a shallow copy of the list
`toString`	`list.toString()`	`string`	Returns a string representation of the list

Examples

`addFirst(value : any)`

Inserts a value at the beginning of the list.

var list = new LinkedList();

list.addFirst(10);   // [10]
list.addFirst(20);   // [20,10]
list.addFirst(30);   // [30,20,10]

println list.get(0);   // 30
println list.get(1);   // 20
println list.get(2);   // 10

var list = new LinkedList();

for var i = 1; i <= 5; i++ do
    list.addFirst(i);
end

// list: [5,4,3,2,1]
println list.get(0);   // 5
println list.get(4);   // 1

`addLast(value : any)`

Inserts a value at the end of the list.

var list = new LinkedList();

list.addLast(10);   // [10]
list.addLast(20);   // [10,20]
list.addLast(30);   // [10,20,30]

println list.get(2);   // 30

`clear()`

Removes all elements from the list, making it empty.

var list = new LinkedList();

list.addLast(1);
list.addLast(2);
list.addLast(3);

println list.size();   // 3

list.clear();

println list.size();     // 0
println list.isEmpty();  // true

`contains(value : any)`

Returns true if the list contains the given value, otherwise false.

var list = new LinkedList();

list.addLast(10);
list.addLast(20);
list.addLast(30);

println list.contains(20);   // true
println list.contains(99);   // false

`get(index : int)`

Returns the element at the specified index.

var list = new LinkedList();

list.addLast(10);
list.addLast(20);
list.addLast(30);

println list.get(0);   // 10
println list.get(1);   // 20
println list.get(2);   // 30

var list = new LinkedList();

list.addLast(1);
list.addLast(2);
list.addLast(3);

list.set(1, 99);

println list.get(1);   // 99

var list = new LinkedList();

list.addLast(1);

try do
    list.get(5);
end
catch(e) do
    println e;   // LinkedList index out of bounds
end

`indexOf(value : any)`

Returns the index of the first occurrence of the given value, or -1 if not found.

var list = new LinkedList();

list.addLast(10);
list.addLast(20);
list.addLast(30);

println list.indexOf(10);   // 0
println list.indexOf(20);   // 1
println list.indexOf(30);   // 2
println list.indexOf(99);   // -1

var list = new LinkedList();

list.addLast(1);
list.addLast(2);
list.addLast(3);

list.removeFirst();   // [2,3]

println list.indexOf(1);   // -1
println list.indexOf(2);   // 0

`isEmpty()`

Returns true if the list contains no elements, otherwise false.

var list = new LinkedList();

println list.isEmpty();   // true

list.addLast(10);

println list.isEmpty();   // false

var list = new LinkedList();

list.addLast(1);
list.addLast(2);

list.clear();

println list.isEmpty();   // true

`peekFirst()`

Returns the first element of the list without removing it, or null if the list is empty.

var list = new LinkedList();

list.addLast(10);
list.addLast(20);

println list.peekFirst();   // 10
println list.size();        // 2 (unchanged)

var list = new LinkedList();

println list.peekFirst();   // null

`peekLast()`

Returns the last element of the list without removing it, or null if the list is empty.

var list = new LinkedList();

list.addLast(10);
list.addLast(20);

println list.peekLast();   // 20
println list.size();       // 2 (unchanged)

var list = new LinkedList();

println list.peekLast();   // null

`removeFirst()`

Removes and returns the first element of the list, or null if the list is empty.

var list = new LinkedList();

list.addLast(10);
list.addLast(20);
list.addLast(30);

var first = list.removeFirst();

println first;         // 10
println list.get(0);   // 20
println list.size();   // 2

var list = new LinkedList();

list.addLast(1);

println list.removeFirst();   // 1
println list.removeFirst();   // null
println list.isEmpty();       // true

`removeLast()`

Removes and returns the last element of the list, or null if the list is empty.

var list = new LinkedList();

list.addLast(10);
list.addLast(20);
list.addLast(30);

var last = list.removeLast();

println last;          // 30
println list.size();   // 2
println list.get(1);   // 20

var list = new LinkedList();

list.addLast(1);

println list.removeLast();   // 1
println list.removeLast();   // null
println list.isEmpty();      // true

`set(index : int, value : any)`

Replaces the element at the specified index and returns the old value.

var list = new LinkedList();

list.addLast(10);
list.addLast(20);
list.addLast(30);

var old = list.set(1, 99);

println old;           // 20
println list.get(1);   // 99

var list = new LinkedList();

list.addLast(1);
list.addLast(2);
list.addLast(3);

list.set(0, 100);
list.set(2, 300);

println list.get(0);   // 100
println list.get(2);   // 300

var list = new LinkedList();

list.addLast(1);

try do
    list.set(5, 10);
end
catch(e) do
    println e;   // LinkedList index out of bounds
end

`size()`

Returns the number of elements in the list.

var list = new LinkedList();

println list.size();   // 0

list.addLast(10);
list.addLast(20);

println list.size();   // 2

var list = new LinkedList();

for var i = 0; i < 5; i++ do
    list.addLast(i);
end

println list.size();   // 5

list.removeFirst();
list.removeLast();

println list.size();   // 3

`toArray()`

Returns a new Array containing all elements of the list in order.

var list = new LinkedList();

list.addLast(10);
list.addLast(20);
list.addLast(30);

var arr = list.toArray();

println arr.get(0);   // 10
println arr.get(1);   // 20
println arr.get(2);   // 30

var list = new LinkedList();

list.addLast(1);
list.addLast(2);
list.addLast(3);

list.removeFirst();   // [2,3]

var arr = list.toArray();

println arr.size();   // 2
println arr.get(0);   // 2
println arr.get(1);   // 

`toString()`

Returns a string representation of the list in traversal order.

var list = new LinkedList();

list.addLast(10);
list.addLast(20);
list.addLast(30);

println list.toString();   // [10 -> 20 -> 30]

var list = new LinkedList();

println list.toString();   // []

General​

Reference​

Instance methods​

Examples​

addFirst(value : any)​

addLast(value : any)​

clear()​

contains(value : any)​

get(index : int)​

indexOf(value : any)​

isEmpty()​

peekFirst()​

peekLast()​

removeFirst()​

removeLast()​

set(index : int, value : any)​

size()​

toArray()​

toString()​