Description
bool
function_exists
( string function_name)
Checks
the
list
of
defined
functions
,
both
built-in
(
internal
)
and
user-defined
,
for
function_name
.
מחזיר
TRUE
במקרה
של
הצלחה
או
FALSE
במקרה
של
כישלון
.
Note that a function name may exist even if the function itself
is unusable due to configuration or compiling options (with the
image
functions being an example). Also note that
function_exists()
will return
FALSE
for constructs, such as
include_once()
and
echo()
.