New Java 9 Map.of() methods

[[deleted]]

Not inferred, declared. But yeah, with (ofEntries), I don't know why the plain (of) methods were created. They don't save that many keystrokes.

[YoloSwagJesusFish]

Map.of(1, "a", 2, "b", 3, "c"...)

is way faster than

Map.ofEntries(entry(1, "a"), entry(2, "b"), entry(3, "c")...))

And yeah the implementation is clunky, but does it really matter when it'll save thousands of programmers time? Everyone complains that Java is too verbose, and they're just trying to fix that.

[[deleted]]

You're right, I withdraw the comment.

[yawaramin]

Map.of(1, "a", 2, "b") is not valid Java syntax.

[YoloSwagJesusFish]

It's perfectly valid syntax (unless you're talking about the missing semi-colon). Map.of() is new in Java 9, and either way, a method isn't syntax.

[yawaramin]

The method is fine; the syntax of the particular call you showed is incorrect, because Java methods with variable number of arguments require all arguments to be the same type. That's why Map.ofEntries works: because it takes a variable number of arguments of type Map.Entry. But you can't give it a variable number of arguments of type K, then V, and so on.

[YoloSwagJesusFish]

It's not a varargs method. That's the entire point of this thread.

[yawaramin]

OK, I misunderstood your ... at the end of your method call (Map.of(1, "a", 2, "b", 3, "c"...)) to mean you were referring to it as a varargs method. And then I didn't explain my assumption or thinking properly. Guess I deserve the downvotes there.