Search code examples

Java array convention: String[] args vs. String args[]

I am currently teaching students as a tutor programming conventions. I've told them that they can find most conventions in the Oracle Code Conventions.

In my last tutorial a student asked if:

public static void main(String args[])


public static void main(String[] args)

is written by convention or if there is a difference. I have never seen the first version before, so I'm very sure that the second one is a convention. But I don't have a source for that.

Can you give me a source (preferably from oracle, like the page I've linked above) that makes clear which of both is convention?

Equivalence of both expressions

I know that both expressions are equivalent:

The JLS 7, p. 292 states:

An array type is written as the name of an element type followed 
by some number of empty pairs of square brackets []. 

but also on p. 293:

The [] may appear as part of the type at the beginning of the declaration, 
or as part of the declarator for a particular variable, or both.

For example:
    byte[] rowvector, colvector, matrix[];
This declaration is equivalent to:
    byte rowvector[], colvector[], matrix[][];

But this doesn't help for the convention-quesiton.

So they are identical (not specs, but here is a source). They produce the same bytecode in a small example, so I'm very sure that they are also identical in praxis.


  • This is not from Oracle but I think it will help.

    It is from Kathy Sierra's book SCJP Sun Certified Programmer for Java 6

    int[] key;
    int key [];

    When declaring an array reference, you should always put the array brackets immediately after the declared type, rather than after the identifier (variable name). That way, anyone reading the code can easily tell that, for example, key is a reference to an int array object, and not an int primitive.