SplFixedArray_splice.php

<?php
$array = new SplFixedArray(2);
$array[0] = 'A';
$array[1] = 'B';
$offset = 0;
if ($array->offsetExists($offset)) {
    $sizeNew = $array->getSize() - 1;
    for ($i = $offset; $i < $sizeNew; ++$i) {
        $array[$offset] = $array[$offset + 1];
    }
    $array->setSize($sizeNew);
}
var_dump($array->toArray());
/**
array(1) {
  [0] =>
  string(1) "B"
}
*/