WordPress at a glance
function is not described

SplFixedArray::valid() public WP 1.0

Check whether the array contains more elements

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

No Hooks.

Return

true|false. true if the array contains any more elements, false otherwise.

Usage

$SplFixedArray = new SplFixedArray();
$SplFixedArray->valid();

Code of SplFixedArray::valid() WP 5.7.1

<?php
public function valid()
{
    if (empty($this->internalArray)) {
        return false;
    }
    $result = next($this->internalArray) !== false;
    prev($this->internalArray);
    return $result;
}