<s>
In	O
some	O
programming	O
languages	O
such	O
as	O
C	B-Language
(	O
and	O
its	O
close	O
descendants	O
like	O
C++	B-Language
,	O
Objective-C	B-Language
,	O
and	O
Java	B-Language
)	O
,	O
static	O
is	O
a	O
reserved	O
word	O
controlling	O
both	O
lifetime	O
(	O
as	O
a	O
static	B-General_Concept
variable	I-General_Concept
)	O
and	O
visibility	O
(	O
depending	O
on	O
linkage	B-Language
)	O
.	O
</s>
<s>
In	O
C	B-Language
and	O
C++	B-Language
,	O
the	O
effect	O
of	O
the	O
static	O
keyword	O
in	O
C	B-Language
depends	O
on	O
where	O
the	O
declaration	O
occurs	O
.	O
</s>
<s>
static	O
may	O
act	O
as	O
a	O
storage	O
class	O
(	O
not	O
to	O
be	O
confused	O
with	O
classes	O
in	O
object-oriented	O
programming	O
)	O
,	O
as	O
can	O
extern	O
,	O
auto	O
and	O
register	B-Language
(	O
which	O
are	O
also	O
reserved	O
words	O
)	O
.	O
</s>
<s>
In	O
these	O
languages	O
,	O
the	O
term	O
"	O
static	B-General_Concept
variable	I-General_Concept
"	O
has	O
two	O
meanings	O
which	O
are	O
easy	O
to	O
confuse	O
:	O
</s>
<s>
(	O
C-family-specific	O
)	O
A	O
variable	O
declared	O
with	O
storage	O
class	O
static	O
.	O
</s>
<s>
A	O
variable	O
declared	O
as	O
static	O
at	O
the	O
top	O
level	O
of	O
a	O
source	O
file	O
(	O
outside	O
any	O
function	O
definitions	O
)	O
is	O
only	O
visible	O
throughout	O
that	O
file	O
(	O
"	O
file	O
scope	O
"	O
,	O
also	O
known	O
as	O
"	O
internal	B-Language
linkage	I-Language
"	O
)	O
.	O
</s>
<s>
Similarly	O
,	O
a	O
static	O
functiona	O
function	O
declared	O
as	O
static	O
at	O
the	O
top	O
level	O
of	O
a	O
source	O
file	O
(	O
outside	O
any	O
class	O
definitions	O
)	O
is	O
only	O
visible	O
throughout	O
that	O
file	O
(	O
"	O
file	O
scope	O
"	O
,	O
also	O
known	O
as	O
"	O
internal	B-Language
linkage	I-Language
"	O
)	O
.	O
</s>
<s>
Variables	O
declared	O
as	O
static	O
inside	O
a	O
function	O
are	O
statically	O
allocated	O
,	O
thus	O
keep	O
their	O
memory	O
location	O
throughout	O
all	O
program	O
execution	O
,	O
while	O
having	O
the	O
same	O
scope	O
of	O
visibility	O
as	O
automatic	B-General_Concept
local	I-General_Concept
variables	I-General_Concept
(	O
auto	O
and	O
register	B-Language
)	O
,	O
meaning	O
they	O
remain	O
local	O
to	O
the	O
function	O
.	O
</s>
<s>
In	O
C++	B-Language
,	O
member	O
variables	O
declared	O
as	O
static	O
inside	O
class	O
definitions	O
are	O
class	B-Application
variables	I-Application
(	O
shared	O
between	O
all	O
class	O
instances	O
,	O
as	O
opposed	O
to	O
instance	B-Application
variables	I-Application
)	O
.	O
</s>
