在 pubspec.yaml 文件中指定库时使用 any 和 nothing 有什么区别？

Question

pubspec.yaml file:

dependencies:
  foo: any
  bar:

When I run pub get command, the latest version of both the libraries are included in my pubspec.lock file. So, what's the difference between these two ways of specifying a library? And if there is none, then why any exists?

Answer 1

According to the Dart.dev page about package dependencies :

The string any allows any version. This is equivalent to an empty version constraint, but is more explicit. Although any is allowed, we don't recommend it.

So, using the keyword any or an empty string is equivalent. However, any is more explicit and not recommended to be used, since if the API of the package you are depending on receives breaking changes in the future, your application won't work correctly.

Answer 2

There's no difference between the two, any is more explicit.

Answer 3

any

will let you update the dependency always to the latest version even if that's mean your project won't be compatible with the library or vice versa.

empty

will let you update the dependency but it will consider the project compatibility with the library or vice versa.