The core concept of this lesson is to learn how to call a function and assign the return value to a variable. Functions act as placeholders for the data they output.Basically, you can assign the output of a function to a variable, just like any normal data. Hi all, I have am developing a URCap that has two different program nodes. One for writing and one for reading. Originally posted on my personal blog. After making a few minor modifications to a function, I was surprised that my program went from a few hundred allocations to millions.