Comment by baq 3 days ago
strong typing: 2 + "2" is an error (e.g. Python vs JS)
static typing: 2 + "2" does not compile/parse (e.g. Python vs mypy, Typescript vs JS)
this is a very simplistic example, but should get you to feel the difference.
Dynamic typing can forbid the latter (at runtime), but it's implementation dependent. There's a further distinction, Latent typing, which is where types are associated with values rather than variables.
But a dynamic language can have types associated with variables, and it can forbid changing those types after their types have been checked the first time.
could also be "4" or 4! 4 seems like it would be the most evil option, honestly
> static typing: 2 + "2" does not compile/parse (e.g. Python vs mypy, Typescript vs JS)
I think this example is not correct, because static typing doesn’t affect how values of different types interact. And while I don’t know of any staticly typed language where specifically `2 + “2”` is a valid expression, statically typed languages definitely can be weakly typed: the most prominent example is C where one can combine values of different types without explicitly converting them to the same type (`2 + 2.0`).
I believe strong/weak and static/dynamic are orthogonal. And my examples are:
- Strong: `2 + “2”` is a error,
- Weak: `2 + “2”` makes 4 (or something else, see the language spec),
- Static: `var x = 2; x = “2”` is an error,
- Dynamic: `var x = 2; x = “2”` is fine.