\S [n]

Where n is

• omitted: display the last value to which the random seed was initialized
• 0N: display the current value of the random seed (since V3.6)
• non-zero integer: re-initialize the seed to n

Note that \S displays the last value to which the seed was initialized: it is not updated as the random-number generator (rng) is used.

q)\S                       / default
-314159i
q)5?10
8 1 9 5 4
q)5?10
6 6 1 8 5
q)\S -314159               / restore default seed
q)5?10                     / same random numbers generated
8 1 9 5 4
q)\S                       / seed is not updated
-314159
q)x:system "S 0N"          / current value of seed
q)r:10?10
q)system "S ",string x     / re-initialize seed
q)r~10?10
1b

Allows user to save and restore state of the rng. (Since V3.6 2017.09.26.)

q)x:system"S 0N";r:10?10;system"S ",string x;r~10?10