Syntactic sugar and Java arrays.

2 Comments Published January 8th, 2010 in Java Tags: Java, Opinion.

Recently I got surprised by following case.

In Java you can declare an array in following valid ways:

String[] strings = new String[] { "foo", "bar" };
// the above is equivalent to the following:
String[] strings = { "foo", "bar" };

So following Java code is perfectly valid:

public class Foo {

    public void doSomething(String[] arg) {}

    public void example() {
        String[] strings = { "foo", "bar" };
        doSomething(strings);
    }

}

Is there any valid reason why, instead, the following code shouldn't be valid?


public class Foo {

    public void doSomething(String[] arg) {}

    public void example() {
        doSomething({ "foo", "bar" });
    }

}

I think, that the above syntax would have been a valid substitute to the varargs introduced in Java 5. And, more coherent with the previously allowed array declarations.

2 Responses to “Syntactic sugar and Java arrays.”

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1 jan Feb 18th, 2010 at 00:21

sure it is not valid…try the following:
doSomething(new String[] {“foo”,”bar”});

why should he know it’s a string array in the first place? ok it’s defined by the method doSomething…but how should he know, that what you are giving in is really such a type :)
2 Luigi Apr 16th, 2010 at 16:34

I am just saying that there’s no logical reason why that shouldn’t compile.

>why should he know it’s a string array in the first place?
> …
>but how should he know, that what you are giving in is really such a type

exactly as the compiler does for the assignation (without needing any cast):

String[] strings = { “foo”, “bar” };