Why does Java allow both int x[] and int[] x?

Question

NOTE: this question was previously marked as a duplicate. It's subtly different, though: the other question asked what the difference is between the two syntaxes; whereas I know there's no difference in meaning, and I'm asking in that case why Java allows both.

Why does Java allow both

int x[];

and

int[] x;

when I declare an array?

The latter makes much more sense: the variable is called x, not x[], and its type is int[], not int. Why not just enforce this? Allowing two different syntaxes seems just to invite confusion and inconsistency. It even appears to make it possible to declare a two-dimensional array as

int[] x[];

which is bordering on unreadable.

Is it something borrowed from C? (Why would C do it that way round, anyway?)

@user3386109 Well, C forces you to use `int x[]`. Therefore if you want a language which lets you use both the C style and the arguably more sane `int[] x`, then you are where Java is. I make no comment on whether this was a good design decision or not. — Philip Kendall, Oct 03 '14 at 22:28
@ericbn thanks for the pointer to the similar question! Mine isn't queer the same, though: that was asking what the difference is, whereas I know there's no difference, and I'm asking why in that case both are allowed. — chiastic-security, Oct 03 '14 at 22:36
@BlueMoon I've edited the question to explain why I think it's a subtly different question. — chiastic-security, Oct 03 '14 at 22:42
@ericbn er, obviously I meant "quite" rather than "queer"... — chiastic-security, Oct 03 '14 at 22:53

score 2 · Answer 1 · answered Oct 03 '14 at 22:24

2

It was added to help C programmers get used to Java.

In Java int[] x; is the preffered way.

answered Oct 03 '14 at 22:24

nana

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OK. It seems a bad idea to help C programmers get used to Java by helping them write bad Java... – chiastic-security Oct 03 '14 at 22:27
I agree, but such is Java. ;) – nana Oct 03 '14 at 22:40
@chiastic-security Since the C way follows use and the Java-preferred way doesn't, I think exactly the opposite. – o11c Oct 03 '14 at 23:08
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@o11c But the C way mixes type and instance declarations. It is a very broken and counter intuitive syntax. It is a pity Java adopted it. – juanchopanza Oct 04 '14 at 07:26

fyr · Accepted Answer · 2014-10-03T22:38:36.963

At least from specification there is no explicit reason for the existence of both. However as follows both ways provide a certain flexibility. With one variable both declarations will provide you with an int array.

x and y are both arrays when:

int[] x, y;

x is an array and y not when:

int x[], y;

See also Oracle Java7 reference. They also say that mixed notation is not recommended noting done the following example:

float[][] f[][], g[][][], h[];  // Yechh!

Why does Java allow both int x[] and int[] x?

2 Answers2