Getting PLS-00103 error when creating a function in Oracle

Question

Im getting a couple of errors within my following function:

CREATE OR REPLACE FUNCTION department_salary
    (emp_dept VARCHAR2, salary NUMBER)
    RETURN NUMBER AS
        dept_sal NUMBER := salary;
    BEGIN
        IF emp_dept = 'MIS' THEN dept_sal := (dept_sal * .10) + dept_sal;
        ELSEIF emp_dept = 'SALES' THEN dept_sal := (dept_sal * .15) + dept_sal;
        ELSEIF emp_dept = 'HR' THEN dept_sal := (dept_sal * .20) + dept_sal;
        ELSE dept_sal := -1;
    END IF;

    RETURN dept_sal;

END;

/

The errors that I get are the following:

LINE/COL ERROR
-------- ----------------------------------------------------------------
7/10     PLS-00103: Encountered the symbol "EMP_DEPT" when expecting one
         of the following:
         := . ( @ % ;

8/10     PLS-00103: Encountered the symbol "EMP_DEPT" when expecting one
         of the following:
         := . ( @ % ;

14/4     PLS-00103: Encountered the symbol ";" when expecting one of the
         following:
         if

Answer 1

The problem is the syntax of the IF statement. In particular, the keyword is ELSIF not ELSEIF (no e). If you change that, the function will compile

SQL> ed
Wrote file afiedt.buf

  1  CREATE OR REPLACE FUNCTION department_salary
  2    (emp_dept VARCHAR2, salary NUMBER)
  3    RETURN NUMBER
  4  AS
  5    dept_sal NUMBER := salary;
  6  BEGIN
  7    IF emp_dept = 'MIS' THEN dept_sal := (dept_sal * .10) + dept_sal;
  8    ELSIF emp_dept = 'SALES' THEN dept_sal := (dept_sal * .15) + dept_sal;
  9    ELSIF emp_dept = 'HR' THEN dept_sal := (dept_sal * .20) + dept_sal;
 10    ELSE dept_sal := -1;
 11    END IF;
 12    RETURN dept_sal;
 13* END;
 14  /

Function created.

If you are writing code like this, however, it is generally clearer to use a CASE statement

SQL> ed
Wrote file afiedt.buf

  1  CREATE OR REPLACE FUNCTION department_salary
  2    (emp_dept VARCHAR2, salary NUMBER)
  3    RETURN NUMBER
  4  AS
  5    dept_sal NUMBER := salary;
  6  BEGIN
  7    CASE emp_dept
  8      WHEN 'MIS'   THEN dept_sal := (dept_sal * .10) + dept_sal;
  9      WHEN 'SALES' THEN dept_sal := (dept_sal * .15) + dept_sal;
 10      WHEN 'HR'    THEN dept_sal := (dept_sal * .20) + dept_sal;
 11      ELSE dept_sal := -1;
 12    END CASE;
 13    RETURN dept_sal;
 14* END;
 15  /

Function created.