avoiding if statements

Question

I was thinking about object oriented design today, and I was wondering if you should avoid if statements. My thought is that in any case where you require an if statement you ca

Answer 1

You must understand what (x > 5) really mean. Assuming that x represents a number, then it basically "classifies" all numbers greater than five. So the code would look like this in a language with python syntax:

class Number(Object):

    # ... Number implementation code ... #

    def doSomething():
        self = 0
        return self

    def doSomethingElse():
        pass

class GreaterThan5(Number):
    def doSomething():
        print "I am " + self

    def doSomethingElse():
        print "I like turtles!"

Then we could run code like the following:

>>> type(3)

>>> type(3+3)

>>> 3.doSomething()
0
>>> (3 + 3).doSomething()
I am 6
>>> (7 - 3).doSomethingElse()
>>>

The automatic type conversion here is important. As far as I am aware, none of the languages today allow you to mess with integers this much.

In the end, you can do in your code whatever. As long as the people reading it can understand immediately. So the polymorphic dispatch on integers or anything unordinary must have really good reasoning behind it.