Another Go Tutorial on Maps

This one is on Maps which are like dictionary types in other language, and some languages call them associative arrays.

I'm trying to get all the Go tutorials done in one er go, and after that I'm going to revisit some of the older C/C++ tutorials and tidy them up and use Codepad.org or ideone.com to let you run the examples. Idedone can even run Go, though I'm not sure whether it's better than play.golang.org. all aspects of Golang