Constructor Injection and Null Object Design Patterns
The Constructor Injection design pattern is a pattern that helps you declare all the required dependencies of a class in it’s constructor. This is useful because it helps you decouple the code, you can specify an interface instead of a concrete type, remember, program to an interface. Also, in the constructor it is easier to guard against null objects. The calling code doesn’t have to worry about null exceptions every time it uses a dependency....