Syntax:scalar CachingIterator::key (void)
Parameters:this function takes no parameters.
Return value:this function returns the key value of the current element.The following programs illustrate the function CachingIterator::key() in PHP:
Program 1:
// Declare the array
$arr
=
array
( ’G’
,
’ e’
,
’ e’
,
’k’
,
’ s’
);
// Create a new CachingIterator
$cachIt
=
new
CachingIterator (
new
ArrayIterator (
$arr
),
CachingIterator::FULL_CACHE
);
foreach
(
$cachIt
as
$element
) {
echo
$cachIt
-> key().
""
;
}
?>
Exit:0 1 2 3 4
Program 2:
// Declare ArrayIterator
$arr
=
array
(
"a"
= >
" Geeks "
,
"b"
= >
"for"
,
"c"
= >
"Geeks" ,
"d"
= >
"Computer"
,
"e"
= >
"Science"
,
"f"
= >
"Portal"
);
// Create a new CachingIterator
$cachIt
=
new
CachingIterator (
new
ArrayIterator (
$arr
),
CachingIterator::FULL_CACHE
);
foreach
(
$cachIt
as
$element
) {
echo
" key: "
.
$cachIt
-> key().
" Value:"
.
$cachIt
-> current().
""
;
}
?>
Exit:key: a Value: Geeks key: b Value: for key: c Value: Geeks key: d Value: Computer key: e Value: Science key: f Value: Portal
Link: https://www.php.net/manual/en/cachingiterator.key.php