C# Programming/Keywords/stackalloc

The keyword stackalloc is used in an unsafe code context to allocate a block of memory on the stack.

int* fib = stackalloc int[100];

In the example above, a block of memory of sufficient size to contain 100 elements of type int is allocated on the stack, not the heap; the address of the block is stored in the pointer fib. This memory is not subject to garbage collection and therefore does not have to be pinned (via fixed). The lifetime of the memory block is limited to the lifetime of the method in which it is defined (there is no way to free the memory before the method returns).

stackalloc is only valid in local variable initializers.

Because Pointer types are involved, stackalloc requires unsafe context. See Unsafe Code and Pointers.

stackalloc is similar to _alloca in the C run-time library.

Note* - From MSDN

C# Keywords
abstract as base bool break
byte case catch char checked
class const continue decimal default
delegate do double else enum
event explicit extern false finally
fixed float for foreach goto
if implicit in int interface
internal is lock long namespace
new null object operator out
override params private protected public
readonly ref return sbyte sealed
short sizeof stackalloc static string
struct switch this throw true
try typeof uint ulong unchecked
unsafe ushort using var virtual
void volatile while
Special C# Identifiers (Contextual Keywords)
add alias async await dynamic
get global nameof partial remove
set value when where yield
Contextual Keywords (Used in Queries)
ascending by descending equals from
group in into join let
on orderby select where