WordPress at a glance
function is not described

SplFixedArray::offsetExists() public WP 1.0

{} It's a method of the class: SplFixedArray{}

No Hooks.

Return

true|false. Null. Nothing.

Usage

$SplFixedArray = new SplFixedArray();
$SplFixedArray->offsetExists( $index );
$index *(string int) (required)*

Code of SplFixedArray::offsetExists() WP 5.7

<?php
public function offsetExists($index)
{
    return array_key_exists((int) $index, $this->internalArray);
}