countbit key [start] [size]

Count the number of set bits (population counting) in a string. Unlike bitcount, it take part of the string by start and size, not start and end.

Parameters

• key -
• start - Optional, inclusive, if start is negative, count from start'th character from the end of string.
• size - Optional, if size is negative, then that many characters will be omitted from the end of string.

Return Value

The number of bits set to 1.

Example

ssdb 127.0.0.1:8888> set a 123
ok
(0.000 sec)
ssdb 127.0.0.1:8888> countbit a 0 1
3
(0.000 sec)
ssdb 127.0.0.1:8888> bitcount a 0 1
6
(0.000 sec)
ssdb 127.0.0.1:8888>