原文
http://redis.io/commands/zlexcount
简介
Count the number of members in a sorted set between a given lexicographical range.
计算有序集合中在指定词典范围内的成员的数量。
语法
ZLEXCOUNT key min max
版本
Available since 2.8.9.
自2.8.9版本可用。
时间复杂度
Time complexity: O(log(N)) with N being the number of elements in the sorted set.
O(log(N))：N是有序集合中元素的数量。
描述
When all the elements in a sorted set are inserted with the same score, in order to force lexicographical ordering, this command returns the number of elements in the sorted set at key with a value between min and max.
当有序集合中插入的所有元素的分数相同时，为了强制进行词典排序，这个命令返回值在min到max之间的元素的数量。
The min and max arguments have the same meaning as described for ZRANGEBYLEX.
参数min和max与ZRANGEBYLEX命令有相同的含义。
Note: the command has a complexity of just O(log(N)) because it uses elements ranks (see ZRANK) to get an idea of the range. Because of this there is no need to do a work proportional to the size of the range.
返回值
Integer reply: the number of elements in the specified score range.
Integer：指定值范围内的元素的数量。
例子
redis> ZADD myzset 0 a 0 b 0 c 0 d 0 e
(integer) 5
redis> ZADD myzset 0 f 0 g
(integer) 2
redis> ZLEXCOUNT myzset - +
(integer) 7
redis> ZLEXCOUNT myzset [b [f
(integer) 5
redis>