Php 向内部数组添加键值对

我已经有了数组中的数据

 $a = array (
     [2011-07-09] => array(['new'] => 12),
     [2011-07-10] => array(['new'] => 15)
 );

现在，我想向内部数组添加另一个键值对，这样输出将如下

 $a = array (
     [2011-07-09] => array(['new'] => 12, ['recurring'] => 52),
     [2011-07-10] => array(['new'] => 15, ['recurring'] => 80)
 );

---

如何执行此操作？

这取决于您计划如何执行

循环

键，具体操作如下：

$a['2011-07-09']['recurring'] = 52;
$a['2011-07-10']['recurring'] = 80;

$a['2011-07-09']['recurring'] = 52;
$a['2011-07-10']['recurring'] = 80;