代码 4-32 获取键值

<?php  
$servant_cat = array("luning"=>"naonao","baibai"=>"catti","liangshuang"=>"titi"); //$servant_cat为关联数组  
$cat = array("naonao","catti","titi"); // $cat为索引数组  

echo $servant_cat["baibai"];   
echo $cat[1];   
?