Checks if value is a member of the set stored at the key key.
检查VALUE是否是SET容器中的成员。
Parameters
key value
Return value
BOOL TRUE if value is a member of the set at key key, FALSE otherwise.
Example
$redis->sAdd('key1' , 'member1');
$redis->sAdd('key1' , 'member2');
$redis->sAdd('key1' , 'member3'); /* 'key1' => {'member1', 'member2', 'member3'}*/
$redis->sIsMember('key1', 'member1'); /* TRUE */
$redis->sIsMember('key1', 'memberX'); /* FALSE */
