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After using var in C# since its inception I personally say this is a non-issue. At worst autocomplete shows the actual type and the available members and usuall

by danbruc 11y ago

After using var in C# since its inception I personally say this is a non-issue. At worst autocomplete shows the actual type and the available members and usually you just know the types after a few minutes even if you are looking into some unknown code.

gravypod 11y ago
I don't see how without an IDE you could do that. Something doesn't just stop being a problem because an IDE helps you avoid it. The explicit nature of Java is what makes it great. What you type is what happens.
- danbruc 11y ago
  Why would you write code without an IDE? And using var doesn't suddenly make things happen randomly, everything is still perfectly well defined, just less verbose. And it is a feature that 99.9 % of the time does what you want, situations in which you want a different type than the inferred one are rare in practice. Actually the only one that I can remember is initializing a variable with some concrete implementation of an interface and desiring the interface type instead of the concrete type. And this one occurs pretty rarely because I think aiming for single assignment is a good thing.
  - gravypod 11y ago
    >And it is a feature that 99.9 % of the time does what you want While typing a variable name explicitly is a feature that 100% of the time does what you want.
    - danbruc 11y ago
      That is why you have the choice to be explicit. You choose between shorter and less redundant code and full control over the type of the variable. What is the point of typing out the same type in a single line twice? HashMap<String, AtomicReference<Foo>> fooMap = new HashMap<String, AtomicReference<Foo>>(); What is the disadvantage of using var? var fooMap = new HashMap<String, AtomicReference<Foo>>(); It's less redundant, easier to read, does not clutter the code and has exactly the same information content. And if you really want the variable to be of type Map<,> nobody stops you.
      - whitenoice 11y ago
        I don't think you have to type it twice even now, if you specify the type on the left, you can just specify <> on the right. So you can write something like - Map<String, List<Xyz>> foo = new TreeMap<>(); This has been present from Java 7. The reason I like this is that when you are parsing through some library code you can just look at the variable declaration and ignore its initialization to figure out what type it is.

by danbruc 11y ago

gravypod 11y ago

I don't see how without an IDE you could do that. Something doesn't just stop being a problem because an IDE helps you avoid it. The explicit nature of Java is what makes it great. What you type is what happens.

danbruc 11y ago
Why would you write code without an IDE? And using var doesn't suddenly make things happen randomly, everything is still perfectly well defined, just less verbose. And it is a feature that 99.9 % of the time does what you want, situations in which you want a different type than the inferred one are rare in practice. Actually the only one that I can remember is initializing a variable with some concrete implementation of an interface and desiring the interface type instead of the concrete type. And this one occurs pretty rarely because I think aiming for single assignment is a good thing.
- gravypod 11y ago
  >And it is a feature that 99.9 % of the time does what you want While typing a variable name explicitly is a feature that 100% of the time does what you want.
  - danbruc 11y ago
    That is why you have the choice to be explicit. You choose between shorter and less redundant code and full control over the type of the variable. What is the point of typing out the same type in a single line twice? HashMap<String, AtomicReference<Foo>> fooMap = new HashMap<String, AtomicReference<Foo>>(); What is the disadvantage of using var? var fooMap = new HashMap<String, AtomicReference<Foo>>(); It's less redundant, easier to read, does not clutter the code and has exactly the same information content. And if you really want the variable to be of type Map<,> nobody stops you.
    - whitenoice 11y ago
      I don't think you have to type it twice even now, if you specify the type on the left, you can just specify <> on the right. So you can write something like - Map<String, List<Xyz>> foo = new TreeMap<>(); This has been present from Java 7. The reason I like this is that when you are parsing through some library code you can just look at the variable declaration and ignore its initialization to figure out what type it is.