# Indeterminacy
There are some pre-defined Wall functions, like rand, now and ptr, that return different values every time a script is invoked and perhaps every time the element is encountered. Let's check them out!
# rand
rand returns a random value generator seeded with integer seed n. The result of rand n is triggered by passing it any value.
w> rand-seeded-with-5 = rand 5
w> rand-seeded-with-5 'hello
0.3425601241
w> rand-seeded-with-5 'hello
0.0943142369
# now
Now is the current timestamp, expressed as a float in microseconds since the beginning of the epoch. Now needs to be invoked with any key as input.
w> now _
1585472068494
# ptr
ptr returns an string representing a ptr to an object in memory.
w> a = 1
w> ptr a
"0x510f32b"