Evaluating Postfix Expression

Instructions:

Evaluate the postfix expression. You can performe an operation on the two topmost values in a stack by moving an operator into the evaluator.

• 1. read postfix expression token by token
• 2. if the token is an operand, push it into the stack
• 3. if the token is a binary operator,
• 3.1 pop the two top most operands from the stack
• 3.2 apply the binary operator with the two operands
• 3.3 push the result into the stack
• 4. finally, the value of the whole postfix expression remains in the stack