BITCOUNTCount set bits in a string, optionally over a byte range.
| 構文 | BITCOUNT key [start end] |
| グループ | string |
| 引数の数 | -2 |
| 導入バージョン | 1.0.0 |
| フラグ | readonly |
| 計算量 | O(N) over the counted bytes |
| Redis 互換性 | differs: the BYTE / BIT unit argument of Redis 7.0 is not accepted — ranges are byte offsets |