What is the purpose of null?

Question

I am in a compilers class and we are tasked with creating our own language, from scratch. Currently our dilemma is whether to include a \'null\' type or not. What purpose do

Answer 1

Use a null object pattern!

If you language is object oriented, let it have an UndefinedValue class of which only one singleton instance exists. Then use this instance wherever null is used. This has the advantage that your null will respond to messages such as #toString and #equals. You will never run into a null pointer exception as in Java. (Of course, this requires that your language is dynamically typed).