Declarations of new types: Union
Pascal C/C++
wtype
w borrower = record
w case boolean of
w false: (EBorr: employee);
w true: (SBorr: student)
w end;
wvar
w someone: borrower;
wtypedef union
w{   employee EBorr;
w     student SBorr;
w} borrower;
wborrower someone;
Example: Suppose the types employee and student have been previously declared: