Array lookup syntax: The syntax for looking up members of an array in Terraform is similar to most other programming languages: ARRAY[]. For example, here’s how you would look up the element at index 1 of var.user_names: var.user_names[1].

The length function: Terraform has a built-in function called length that has the following syntax: length(). As you can probably guess, the length function returns the number of items in the given ARRAY. It also works with strings and maps