Decrements the integer value of a key by one. Uses 0 as initial value if the key doesn’t exist.
DECR key
Decrements the number stored at key by one. If the key does not exist, it is set to 0 before performing the operation. An error is returned if the key contains a value of the wrong type or contains a string that can not be represented as integer. This operation is limited to 64 bit signed integers.
See INCR for extra information on increment/decrement operations.
Integer reply: the value of the key after decrementing it.
O(1)
@fast @string @write
127.0.0.1:6379> SET mykey "10"
OK
127.0.0.1:6379> DECR mykey
(integer) 9
127.0.0.1:6379> SET mykey "234293482390480948029348230948"
OK
127.0.0.1:6379> DECR mykey
(error) ERR value is not an integer or out of rangeAPPEND, DECRBY, DELIFEQ, GET, GETDEL, GETEX, GETRANGE, GETSET, INCR, INCRBY, INCRBYFLOAT, LCS, MGET, MSET, MSETNX, PSETEX, SET, SETEX, SETNX, SETRANGE, STRLEN, SUBSTR.