## set
~~~
$redis->delete('set1');
$redis->sAdd('set1','A'); //添加元素
$redis->sAdd('set1','B');
$redis->sAdd('set1','C');
$redis->sAdd('set1','C');
$val = $redis->sCard('set1'); //获取元素个数
var_dump($val);
$vals = $redis->sMembers('set1'); //获取元素元素，返回数组
var_dump($vals);
~~~
