Returns the members of a set resulting from the intersection of all the sets held at the specified keys. If just a single key is specified, then this command produces the members of this set. If one of the keys is missing, FALSE is returned.
返回指定SETS集合的交集结果。如果只是指定了一个SET集合，那么返回该SET集合。如果在参数中有参数错误，那么则返回FLASE。
Parameters
key1, key2, keyN: keys identifying the different sets on which we will apply the intersection.
参数列表，代表不同的SET集合。
Return value
Array, contain the result of the intersection between those keys. If the intersection beteen the different sets is empty, the return value will be empty array.
返回数组，数组中的结果为所有SET集合的交集。如果所涉及到的SET集合没有交集结果，那么将返回一个空数组。
Examples
$redis->sAdd('key1', 'val1');
$redis->sAdd('key1', 'val2');
$redis->sAdd('key1', 'val3');
$redis->sAdd('key1', 'val4');
$redis->sAdd('key2', 'val3');
$redis->sAdd('key2', 'val4');
$redis->sAdd('key3', 'val3');
$redis->sAdd('key3', 'val4');
var_dump($redis->sInter('key1', 'key2', 'key3'));
Output:
array(2) {
[0]=>
string(4) "val4"
[1]=>
string(4) "val3"
}