What is typing discipline

Question

C# typing discipline is described by Wikipedia as: static, dynamic, strong, safe, nominative, partially inferred

What is the definition of typing discipline? What do those terms mean, and how do they connect to language?

Answer 1

Wikipedia's typing discipline relates to the type system employed by C# (just try clicking the link, it will lead you to the Type System article).

What they imply is as follows:

Static - At compilation time, the types are determined (the compiler wants to know the type before it runs)

Dynamic - Types are determined at runtime (in C#, this is made easier by the dynamic keyword, which was introduced in C# 4.0).

Safe - The language doesn't allow you to break any of the type rules. Without a cast declared, you can't add strings into a list of complex types, for example.

Powerful - Take a look at Eric Lippert's article on the subject rather than me trying to explain it.

Nominative - Type equivalence is determined by the type's name (what this means is that two types with the same fields but different names are treated as different types)

Partially inferred - During compile-time, the compiler can assume the type you're referring to (this is the var keyword in C#, which allows you to not define the type in your code, but it's still determined in a static and strong fashion at compile-time).