Adds an object (entity) to a selection set, or creates a new selection set
(ssadd [ename [ss]])
If called with no arguments, ssadd constructs a new selection set with no members. If called with the single entity name argument ename, ssadd constructs a new selection set containing that single entity. If called with an entity name and the selection set ss, ssadd adds the named entity to the selection set.
The modified selection set passed as the second argument, if successful; otherwise nil.
When adding an entity to a set, the new entity is added to the existing set, and the set passed as ss is returned as the result. Thus, if the set is assigned to other variables, they also reflect the addition. If the named entity is already in the set, the ssadd operation is ignored and no error is reported.
Set e1 to the name of the first entity in drawing:
Command: (setq e1 (entnext))
<Entity name: 1d62d60>
Set ss to a null selection set:
Command: (setq ss (ssadd))
<Selection set: 2>
The following command adds the e1 entity to the selection set referenced by ss:
Command: (ssadd e1 ss)
<Selection set: 2>
Command: (setq e2 (entnext e1))
<Entity name: 1d62d68>
Command: (ssadd e2 ss)
<Selection set: 2>