Is there any function available to check if variable value is "User" or "group"?

AFAIK there is no in-built function to verify weather it is a user or group.
I think you can make a use of typeof() function to check this. This function return integer value for the type.
Suppose,
if variable is of type "User" then it will return = 4
If variable is of type "Group" then it will return = 5
If variable is of type "User or Group" then it will return = 27

Let us know if that works for you.

Typeof(ri!assignee) always return 27 because variable type is "User or Group".

I have found one alternative to your ask - create an expression rule and pass one input parameter of type (User or Group). Write below code inside expression rule, verify it.

with(
local!castValue: cast(3, ri!input),
find("[", local!castValue, 0) /* 1 means Group, 0 means User*/
)

Let me know if that works.

Also, remember - check for NULL value of the input parameter before you cast it (handle NULL check). Also, you can return TRUE or FALSE based on the result.

Thanks durgeshk! It is working but I also found a function to resolve the issue. runtimetypeof function returns runtime type of variable.

The runtimetypeof has worked for me in the past.

runtimetypeof() is the most appropriate function for this use case. note that an appian datatype like 'user or group' is a 'compound/union datatype' since the value can be either of the type of group or user.

@amirh504,

Below code snippet would be helpful.
Here the input ri!userOrGroup is User or Group type List
"Users - " & touser(
ri!userOrGroup
) & ", Groups - " & togroup(
ri!userOrGroup
)

Please add the required conditions or logic based on your requirement.

We had same requirement for a project, and I tried some solutions given here but they didn't work for me.
So here is my solution, see if it helps you:

if(find("Group",tostring(try(
togroup(ri!input),touser(ri!input))),1),"Group",
isusernametaken(tostring(ri!input)),"user","notUserorGroup")

Hi Sneha,
Its always good to avoid using internal functions like try(), these internal functions evaluations might be changed from one release to other release.