类似于这样子的数据，如果小弟我有一个变量nId，怎么遍历后去的知道他的name

$s =<<< TXT<br />
[ {<br />
  "Id" : "t1sd",<br />
  "Name" : "xiaoxiao",<br />
  "Namea" : "测试样子",<br />
  "nId" : "csd2"<br />
}, {<br />
  "Id" : "ae2",<br />
  "Name" : "张三",<br />
  "Namea" : "哈哈",<br />
  "nId" : "20af"<br />
}, {<br />
  "Id" : "c3P",<br />
  "Name" : "用户1",<br />
  "Namea" : "dingding",<br />
  "nId" : "4fc"<br />
} ]<br />
TXT;<br />
$nId = '4fc';<br />
$t = json_decode($s, true);<br />
$r = array_filter($t, function($a)use($nId) { return $a['nId'] == $nId; });<br />
echo current($r)['Name'];<br />