Concept of "interfaces" covered before chapter 7

[fxdgear]

Section 3.3 we are covering Type Assertion http://www.golangbootcamp.com/book/types#sec-type-assertion.

The examples in the book are going over interface type assertions. I, being new to go, don't quite understand interfaces yet. So these examples are not helpful at all.

It would be better if:

1. we covered what an interface is before section 3
2. used a different type in the examples.

Similarly, in this example we are also going over maps which aren't covered till the next section in section 4.

Maybe Type Assertion should be moved to after all these other concepts have been covered. So that the code examples aren't so confusing to new go programmers.