Static variable

In <a href="/facts/Computer_programming/QmSsFnu0">computer programming</a>, a static variable is a <a href="/facts/Variable_(programming)/VoCKtwml">variable</a> that has been <a href="/facts/Memory_allocation/vthLkUpz">allocated</a> "statically", meaning that its <a href="/facts/Variable_lifetime/VoCKtwml">lifetime</a> (or "extent") is the entire run of the program. This is in contrast to shorter-lived <a href="/facts/Automatic_variable/S6KdHa7p">automatic variables</a>, whose storage is <a href="/facts/Stack_allocation/Wem3dQa6">stack allocated</a> and deallocated on the <a href="/facts/Call_stack/1sMt713v">call stack</a>; and in contrast to <a href="/facts/Dynamic_memory_allocation/vthLkUpz">dynamically allocated</a> objects, whose storage is allocated and deallocated in <a href="/facts/Heap_memory/vthLkUpz">heap memory</a>.
<a href="/facts/Variable_lifetime/VoCKtwml">Variable lifetime</a> is contrasted with <a href="/facts/Scope_(computer_science)/bbj6AFMo">scope</a> (where a variable can be used): "global" and "local" refer to scope, not lifetime, but scope often implies lifetime. In many languages, <a href="/facts/Global_variable/XWF9zC08">global variables</a> are always static, but in some languages they are dynamic, while <a href="/facts/Local_variable/q8sIjyhx">local variables</a> are generally automatic, but may be static.
In general, static memory allocation is the allocation of memory at <a href="/facts/Compile_time/yCdI3oqn">compile time</a>, before the associated program is executed, unlike <a href="/facts/Dynamic_memory_allocation/vthLkUpz">dynamic memory allocation</a> or <a href="/facts/Automatic_memory_allocation/S6KdHa7p">automatic memory allocation</a> where memory is allocated as required at <a href="/facts/Run_time_(program_lifecycle_phase)/lCxKsrzB">run time</a>.

Static variable open-in-new

Static variable