-- https://docs.oracle.com/en/database/oracle/oracle-database/23/lnpls/plsql-subprograms.html
DECLARE
  FUNCTION test (p INTEGER) RETURN INTEGER IS
  BEGIN
    DBMS_OUTPUT.PUT_LINE('p = ' || p);
    RETURN p;
  END test;

BEGIN
  DBMS_OUTPUT.PUT_LINE('test(p) = ' || test(0.66));
END;
/