Stack<T>

Struct · namespace System · Since 0.09

struct Stack<T>

A stack of values: last in, first out.

var undo = Stack<string>.Create();
undo.Push("move");
undo.Push("delete");
string last = undo.Pop();        // "delete"
if (undo.TryPop() is string s)   // no panic when the stack is empty
    ...

Like List<T>, a Stack is a small handle to shared storage: copies see the same elements. foreach and Get(i) go from the top (the next Pop) to the bottom.

Static methods

Name	Description
Create	A new, empty stack.

Create

static Stack<T> Create()

A new, empty stack.

static Stack<T> Create(int capacity)

A new, empty stack with room for capacity elements before it has to grow.

Methods

Name	Description
IsCreated	Whether the stack has storage: made by Create(), not the zero value (which cannot change).
Count	The number of elements.
Push	Puts value on top of the stack.
Pop	Removes and returns the top element.
TryPop	Removes and returns the top element, if there is one.
Peek	The top element, without removing it.
TryPeek	The top element without removing it, if there is one.
Get	The element index places below the top (0 is the top).
Contains	Whether an element equals value (IEquatable).
Clear	Removes all elements.
ToArray	The elements from the top to the bottom (the order Pop would return them).

IsCreated

bool IsCreated()

Whether the stack has storage: made by Create(), not the zero value (which cannot change).

Since 0.26

Count

int Count()

The number of elements.

Push

void Push(T value)

Puts value on top of the stack.

Panics when the stack was not created (Stack<T>.IsCreated).

Pop

T Pop()

Removes and returns the top element.

Panics when the stack is empty (Stack<T>.TryPop does not).

TryPop

Optional<T> TryPop()

Removes and returns the top element, if there is one.

Returns nothing (null) when the stack is empty.

Peek

T Peek()

The top element, without removing it.

Panics when the stack is empty (Stack<T>.TryPeek does not).

TryPeek

Optional<T> TryPeek()

The top element without removing it, if there is one.

Returns nothing (null) when the stack is empty.

Get

T Get(int index)

The element index places below the top (0 is the top).

Panics when index is not in 0 to Count() - 1.

Contains

bool Contains(T value) where T : IEquatable<T>

Whether an element equals value (IEquatable).

Clear

void Clear()

Removes all elements.

ToArray

T[] ToArray()

The elements from the top to the bottom (the order Pop would return them).