The ArrayIterator::offsetExists() function is an inbuilt function in PHP which is used to check the existence of offset at the given index.
Syntax:
bool ArrayIterator::offsetExists( mixed $index )
Parameters: This function accepts single parameter $index which holds the index value to check the existence of offset.
Return Value: This function returns TRUE if the offset exists, otherwise returns FALSE.
Below programs illustrate the ArrayIterator::offsetExists() function in PHP:
Program 1:
<?php   // Declare an ArrayIterator $arrItr = new ArrayIterator(     array(         "a" => 4,         "b" => 2,         "g" => 8,         "d" => 6,         "e" => 1,         "f" => 9     ) );   // Display the offset value var_dump($arrItr->offsetGet("a"));   // Check the existence of offset var_dump($arrItr->offsetExists("a"));   // Unset the offset value var_dump($arrItr->offsetUnset("a"));     // Check the existence of offset var_dump($arrItr->offsetExists("a"));   ?> |
int(4) bool(true) NULL bool(false)
Program 2:
<?php      // Declare an ArrayIterator $arrItr = new ArrayIterator(     array(         "for", "Geeks", "Science",         "Geeks", "Portal", "Computer"    ) );       // Print the value at index 1 echo $arrItr->offsetGet(1) . "\n";   // Check the existence of offset var_dump($arrItr->offsetExists(1));   // Unset the offset value var_dump($arrItr->offsetUnset(1));   // Check the existence of offset var_dump($arrItr->offsetExists(1));     // Print the value at index 0 echo $arrItr->offsetGet(0) . "\n";   // Check the existence of offset var_dump($arrItr->offsetExists(0));   // Unset the offset value var_dump($arrItr->offsetUnset(0));   // Check the existence of offset var_dump($arrItr->offsetExists(0));   ?> |
Geeks bool(true) NULL bool(false) for bool(true) NULL bool(false)
Reference: https://www.php.net/manual/en/arrayiterator.offsetexists.php
