(Latest Revision: Tue Oct 31 22:55:00 PST 2000 )
X A B - Y Z + * -The pseudo code algorithm for evaluating the expression is:
FOR (each character Ch in the string) { IF (Ch is an operand) THEN Push value that operand Ch represents onto the stack ELSE /* Ch is an operator named Op */ { // evaluate and push the result Operand2 = top of stack /* top not removed. */ Pop the stack /* Pop removes top. */ Operand1 = top of stack Pop the stack Result = Operand1 Op Operand2 Push Result onto stack } }