Dependency injection: do we all need to know that?
One of my friend (he is a .NET/C++ developer, as I am) asked me:

> Dependency injection: do we all need to know that? Why?

Could you please tell:

 1. Your opinion: do we really need to know that pattern and how to implement it?
 2. Good reference (link) that could explain "why?"

Thank you a lot.

P.S. I am understanding that I am asking a lot... but I can't find good reference myself...
Dependency injection: do we all need to know that?
===

One of my friend (he is a .NET/C++ developer, as I am) asked me:

> Dependency injection: do we all need to know that? Why?

Could you please tell:

 1. Your opinion: do we really need to know that pattern and how to implement it?
 2. Good reference (link) that could explain "why?"

Thank you a lot.

P.S. I am understanding that I am asking a lot... but I can't find good reference myself...