Built-In Functions

Built-in functions are a library of utility methods and are frequently used to generate new values for variables and change existing ones.

These functions can be called from two places in the flow:

1. The dedicated function call flow node - node functions;

2. As a part of an expression authored via an expression editor - expression functions.

The main difference between node and expression functions is whether they have an ability to modify variables that are passed to them as input arguments.

The functions available in the function call flow node can directly change values stored in the argument variables - for example, remove an element from an existing array.

The functions available in the expression editor are so-called pure functions. i.e. they leave all input arguments unchanged and only produce a new return value, which can then be stored in a variable, used as a part of a condition check. or passed to yet another function as an argument.

a pure function has the following properties:

1. the function return values are identical for identical arguments (no variation with local static variables, non-local variables, mutable reference arguments or input streams), and

2. the function has no side effects (no mutation of local static variables, non-local variables, mutable reference arguments or input/output streams).