vhandit

What issues do we concern when implementing and maintaining systems? One of the most concern is debugging during maintenance: "this code crashed because it observed some unexpected value." Then, it turns out that the ideas of  no side effects  and  immutability , which functional programming promotes, can help. Shared mutable data is the root cause Shared mutable data are read and updated by more than one of the methods. Share mutable data structures make it harder to track changes in different parts of your program. An immutable object is an object that can't change its state after it's instantiated so it can't be affected by the actions of a function. It would be a dream to maintain because we wouldn't have any bad surprises about some object somewhere that unexpectedly modifies a data structure. A new thinking: Declarative programming There are two ways thinking about implementing a system by writing a program. - Imperative programming: has...