Why can't I create a new Java array inline?

Question

Why does the first one work and the second not work?

1) OK

String[] foo = {"foo"};
bar.setArray(foo);

2) BAD

bar.setArray({"foo"});

Is there a quick way to create a String[] on a single line?

Answer 1

bar.setArray(new String[] { "foo" });

I believe this format is required because Java does not want to imply the array type. With the array initialization format, the type is defined explicitly by the assigned variable's type. Inline, the array type cannot be inferred.

Answer 2

You should use this:

bar.setArray(new String[] {"foo"});

Answer 3

As others have said:

bar.setArray(new String[] {"foo"});

It was planned to allow getting rid of the new String[] in J2SE 5.0, but instead we have varargs. With varargs, you can slightly change the the declaration of setArray to use ... in place of [], and ditch the new String[] { }.

public final class Bar {
    public void setArray(String... array) {
    [...]
}

[...]
    bar.setArray("foo");