The HCL language includes a number of built-in functions that you can call from within expressions to transform and combine values. The general syntax for function calls is a function name followed by comma-separated arguments in parentheses:
max(5, 12, 9)
HCL functions are executed on job submission and cannot be combined with client side interpolation.
The HCL language does not support user-defined functions, and so only the functions built in to the language are available for use. The navigation for this section includes a list of all of the available built-in functions.