PHP | ArrayIterator key() Function Last Updated : 21 Nov, 2019 Comments Improve Suggest changes Like Article Like Report The ArrayIterator::key() function is an inbuilt function in PHP which returns the current key of the array element. Syntax: mixed ArrayIterator::key( void ) Parameters: This function does not accept any parameters. Return Value: This function returns the current array key. Below programs illustrate the ArrayIterator::key() function in PHP: Program 1: php <?php // Declare an ArrayIterator $arrItr = new ArrayIterator( array('G', 'e', 'e', 'k', 's', 'f', 'o', 'r') ); // Loop to display the array iterator key foreach($arrItr as $element) { echo $arrItr->key() . "\n"; } ?> Output: 0 1 2 3 4 5 6 7 Program 2: php <?php // Declare an ArrayIterator $arrItr = new ArrayIterator( array( "a" => "Geeks", "b" => "for", "c" => "Geeks" ) ); // Append the element into array iterator $arrItr->append("Computer"); $arrItr->append("Science"); $arrItr->append("Portal"); // Display the key and its value of // array iterator foreach($arrItr as $element) { echo "key: " . $arrItr->key() . " Value: " . $arrItr->current() . "\n"; } ?> Output: key: a Value: Geeks key: b Value: for key: c Value: Geeks key: 0 Value: Computer key: 1 Value: Science key: 2 Value: Portal Reference: https://www.php.net/manual/en/arrayiterator.key.php Comment More infoAdvertise with us Next Article PHP | ArrayIterator key() Function J jit_t Follow Improve Article Tags : Web Technologies PHP PHP-function Similar Reads PHP | ArrayIterator next() Function The ArrayIterator::next() function is an inbuilt function in PHP which is used to move the iterator to the next entry. Syntax: void ArrayIterator::next( void ) Parameters: This function does not accept any parameters. Return Value: This function does not return any value. Below programs illustrate t 1 min read PHP | ArrayIterator ksort() Function The ArrayIterator::ksort() function is an inbuilt function in PHP which is used to sort the array element by key. Syntax: void ArrayIterator::ksort( void ) Parameters: This function does not accept any parameters. Return Value: This function does not return any value. Below programs illustrate the A 2 min read PHP | DirectoryIterator key() Function The DirectoryIterator::key() function is an inbuilt function in PHP which is used to return the key for the current DirectoryIterator item. Syntax: string DirectoryIterator::key( void ) Parameters: This function does not accept any parameters. Return Value: This function returns the key for the curr 2 min read PHP array_âkey_âfirst() Function The array_âkey_âfirst() function is an inbuilt function in PHP that is used to get the first key of an array. This function returns the first key without affecting the internal array pointer. Syntax: int|string|null array_key_first(array $array) Parameters: This function accepts a single parameter $ 1 min read PHP | ArrayIterator getFlags() Function The ArrayIterator::getFlags() function is an inbuilt function in PHP which is used to get the behavior of flags of array iterator. Syntax: int ArrayIterator::getFlags( void ) Parameters: This function does not accept any parameters. Return Value: This function returns the behavior flags of the Array 1 min read Like