Named Item Selector "."

<variable> = <list> . <name>

Operators: Item selector "[]"
Operators: Select "? :"Select named item in Data Types: Lists and arrays
Item selector "[]": Lists
Glossary: list, list_vallist.

e.g.:

ar a={1,2,3};
ar a.b=4;
ename a[2]="z"; Instructions: putput a.z,a.b;