Syntax

Memcached incr and decr commands are used to increment or decrement the numeric value of an existing key. If the key is not found, then it returns NOT_FOUND. If the key is not numeric, then it returns CLIENT_ERROR cannot increment or decrement non-numeric value. Otherwise, ERROR is returned.

The basic syntax of Memcached delete command is as shown below

incr key increment_value

incr command may produce one of the following result −

NOT_FOUND indicates that the key does not exist.
CLIENT_ERROR indicates that value is not numeraical.
ERROR indicates any other error such as syntax error.

Example

In this example, we use visitors as key and set 10 initially into it, there after we increment the visitors by 5.

set visitors 0 900 2
10
STORED
get visitors
VALUE visitors 0 2
10
END
incr visitors 5
15
get visitors
VALUE visitors 0 2
15
END

decr is contrary to incr.