The CachingIterator::key() function is an inbuilt function in PHP which is used to return the key for the current element.
Syntax:
scalar CachingIterator::key( void )
Parameters: This function does not accept any parameters.
Return Value: This function returns the key value of the current element.
Below programs illustrate the CachingIterator::key() function in PHP:
Program 1:
<?php // Declare an 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() . "\n" ;
} ?> |
Output:
0 1 2 3 4
Program 2:
<?php // Declare an 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() . "\n" ;
} ?> |
Output:
key: a Value: Geeks key: b Value: for key: c Value: Geeks key: d Value: Computer key: e Value: Science key: f Value: Portal
Reference: https://www.php.net/manual/en/cachingiterator.key.php