var seems like a bad idea to me. One of the things I like about Java is (strong?) typing. Recently learning C# and was put off by 'var'. Why is it a good idea?
'var' in C# and Java doesn't change strong or static typing at all. It's just type inference. Your code is still statically typed, the compiler and IDE will catch errors. It's just that it's smart enough to infer the types of redundant things instead of making you type it.
So instead of typing:
AbstractConcreteFactoryFactory factory = new AbstractConcreteFactoryFactory();
You can just type it only once:
var factory = new AbstractConcreteFactoryFactory();
`Simple<List<Map<String, Demo>, OtherList<Map<Int, String>>` is a little bit painful.
I use scala and basically most often at least public Methods should (in scala you can omit even that, however some functional libraries need a return type) have a explicit type, which most often is enough.
So instead of typing:
You can just type it only once: