Is there a function to calculate the length of an array (list)?


I see very little documentation on lists and how to work with them. I want to be able to run a for loop based on the length of a list that is dynamically changed. I also want to be able to remove all values stored in a list at once with one command or i could us a for loop again knowing the length of array would help to use this for loop to clear each value one by one.


I know another workaround to this would be to define that a list will never be more than N and therefore create a for loop for 0 to N and then have a sub condition that checks each value within F[0] … F[N] for a non null value as an exit routine.


You can run a For loop on each item in a device array. You can also use the count() function to return the number of items in an array.

More details needed, like a sample piston or actual application, before any solid answers or samples can be provided.




Try this for an example.

You can ignore the IFTTT trigger as this was just a way for me to manually trigger this piston to test my code, but i was playing around with the way webCoRE handles lists / arrays and how to get them to print out using a for loop with the length of the array as the final interval value of For loop.


Yep, exactly right! If you run into any snags using arrays, just post up and someone will certainly help out!


I am trying to figure out the length of an array to iterate in a for loop, but some of values are ‘0’ so count() returns the wrong count. It looks like for…each only works for devices.

I would also like to use nested arrays, but I have had no luck trying to get this to work.


Not sure if we have size() available, been a while :grinning:


Hi, I tried the count() function but its not considering empty value… do you know a workaround for this?


I found it, size() works great!