A[b].c[d].e
------解决方案--------------------
<?php
$arr = array(
'A[a]'=>array('C[d]'=>array('e'=>'hello world')),
);
print_r($arr);
print_r($arr['A[a]']);
没发现报错，你能把上下文给弄全了吗
------解决方案--------------------
$arr = array("a"=>array(1,2,3),"b"=>array("c"=>array("d"=>array("e"=>"Tom","f"=>"BeiJing"))));
$smarty->assign("A",$arr);
$smarty->display("testTwo.html");
<!--testTwo.html-->
{$A['b'].c['d'].e}
<!-- 输出Tom -->