I will show how to evaluate Postfix expression for your interviews as a C# developer. When you have interviews, you never know what they will ask you. Sometimes, the easiest question could be the most complicated thing. I don't know you, but I found this snap test interview quite boring. For example, when in the real work you have to evaluate a Postfix expression?
The full explanation of this code is on my post "Evaluate Postfix expression for interviews" on PureSourceCode.