php怎么去掉数组前一个元素

<?php
header('content-type:text/html;charset=utf-8');   
$arr = array("a" => "pear", "b" => "strawberry", "223", "c" => "cherry");
var_dump($arr);
$value=array_values($arr);
var_dump($value);
?>

<?php
header('content-type:text/html;charset=utf-8');   
$arr = array("a" => "pear", "b" => "strawberry", "223", "c" => "cherry");
var_dump($arr);
$value=array_values($arr);
var_dump($value);
$index=array_search("223",$value);
echo $index;
?>

<?php
header('content-type:text/html;charset=utf-8');   
$arr = array("a" => "pear", "b" => "strawberry", "223", "c" => "cherry");
var_dump($arr);
$value=array_values($arr);
var_dump($value);
$index=array_search("223",$value);
echo "指定元素的索引：".$index;
array_splice($arr,$index-1,1);
var_dump($arr);
?>