Mad, Crazy etc... Question but...
Reference: https://en.wikipedia.org/wiki/Design_by_contract
So the integration of interfaces in object-oriented programming implements the ability to check if a method/property is contained inside an object... but if you're creating the Instance of the object, surely you'd know if it had a certain method?
Reference: https://msdn.microsoft.com/en-us/library/87d83y5b.aspx
Makes no sense why you'd ever need an interface because not even a user input would control any methods, properties or instances.
Reference: https://stackoverflow.com/a/26437718/5897602
Could someone explain why you'd ever need to actually need to need to implement a interface on a class?
Thanks in advance - trying to get my head around them.