Database Reference
In-Depth Information
the corresponding parameter value. If the parameter is not available, the function re‐
turns an unset value. (
get_param_val()
uses a helper function,
strip_slash_help
er()
, which is discussed shortly.)
function
get_param_val
(
$name
)
{
$val
=
NULL
;
if
(
isset
(
$_GET
[
$name
]))
$val
=
$_GET
[
$name
];
else
if
(
isset
(
$_POST
[
$name
]))
$val
=
$_POST
[
$name
];
if
(
isset
(
$val
)
&&
get_magic_quotes_gpc
())
$val
=
strip_slash_helper
(
$val
);
return
(
$val
);
}
To use this function to obtain the value of a single-valued parameter named
id
, call it
like this:
$id
=
get_param_val
(
"id"
);
Test
$id
to determine whether the
id
parameter was present in the input:
if
(
isset
(
$id
))
...
id
parameter
is
present
...
else
...
id
parameter
is
not
present
...
For a form field that might have multiple values (such as a checkbox group or a multiple-
pick scrolling list), represent it in the form using a name that ends in
[]
. For example,
a list element constructed from the
SET
column
accessories
in the
cow_order
table
has one item for each permitted set value. To make sure PHP treats the element value
as an array, name the field
accessories[]
, not
accessories
. (See
Recipe 20.3
for an
example.) When the form is submitted, PHP places the array of values in a parameter
named without the
[]
. To access it, do this:
$accessories
=
get_param_val
(
"accessories"
);
The value of the
$accessories
variable is an array, whether the parameter has multiple
values, a single value, or even no values. The determining factor is not whether the
parameter actually
has
multiple values, but whether you named the corresponding field
in the form using
[]
notation.
The
get_param_val()
function checks the
$_GET
and
$_POST
arrays for parameter val‐
ues. Thus, it works correctly regardless of whether the request was made by
get
or
post
, or whether
register_globals
is enabled. It assumes only that
track_vars
is
enabled.
get_param_val()
also works correctly regardless of whether magic quoting is enabled.
It uses a helper function
strip_slash_helper()
that performs backslash stripping from
parameter values if necessary:
