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javaarrayssyntax
Johannes Schaub - litb
Johannes Schaub - litb

Reputation: 507095

Weird "[]" after Java method signature

I looked at some Java code today, and I found some weird syntax:

public class Sample {
  public int get()[] {
    return new int[]{1, 2, 3};
  }
}

I thought that can't compile and wanted to fix what I thought was a typo, but then I remembered the Java compiler did actually accept it!

Can someone please help me understand what it means? Is it an array of functions?

Upvotes: 125

Views: 8035

Answers (4)

Mehrdad Afshari
Mehrdad Afshari

Reputation: 422076

It's a method that returns an int[].

Java Language Specification (8.4 Method Declarations)

The declaration of a method that returns an array is allowed to place some or all of the bracket pairs that denote the array type after the formal parameter list. This syntax is supported for compatibility with early versions of the Java programming language. It is very strongly recommended that this syntax is not used in new code.

Upvotes: 114

AProgrammer
AProgrammer

Reputation: 52294

As there is a C tag, I'll point out that a similar (but not identical) notation is possible in C and C++:

Here the function f returns a pointer to an array of 10 ints.

int tab[10];

int (*f())[10]
{
    return &tab;
}

Java simply doesn't need the star and parenthesis.

Upvotes: 12

Costis Aivalis
Costis Aivalis

Reputation: 13728

That's a funny Question. In java you can say int[] a;, as well as int a[];.
From this perspective, in order to get the same result just need to move the []
and write public int[] get() {.
Still looks like the code came from an obfuscator...

Upvotes: 22

davin
davin

Reputation: 45545

java's syntax allows for the following:

int[] intArr = new int[0];

and also

int intArr[] = new int[0];

which looks more fmiliar coming from the c-style syntax.

so too, with a function, the name can come before or after the [], and the type is still int[]

Upvotes: 5

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