01.
$array
= [
02.
0 =>
''
,
03.
1 => false,
04.
2 => true,
05.
3 => null,
06.
4 => [],
07.
5 =>
new
\stdClass(),
08.
];
09.
10.
11.
var_dump(isset(
$array
[0]));
12.
var_dump(isset(
$array
[1]));
13.
var_dump(isset(
$array
[2]));
14.
var_dump(isset(
$array
[3]));
15.
var_dump(isset(
$array
[4]));
16.
var_dump(isset(
$array
[5]));
17.
var_dump(isset(
$array
[99]));
18.
19.
echo
'<hr>'
. PHP_EOL;
20.
21.
var_dump(
array_key_exists
(0,
$array
));
22.
var_dump(
array_key_exists
(1,
$array
));
23.
var_dump(
array_key_exists
(2,
$array
));
24.
var_dump(
array_key_exists
(3,
$array
));
25.
var_dump(
array_key_exists
(4,
$array
));
26.
var_dump(
array_key_exists
(5,
$array
));
27.
var_dump(
array_key_exists
(99,
$array
));