Question

When I create a new array, I do something like this.

int[] anArray = {1, 2, 3};

But I’ve seen some people do something like.

int[] anArray = new int[] {1, 2, 3};

I understand what it does, but I don’t understand the purpose of it. Is there a benefit of doing it one way over another?

Thanks

Answer 1

There’s no difference in behaviour where both are valid. They are covered in section 10.6 and 15.10 of the Java language specification.

However the first syntax is only valid when declaring a variable. So for example:

 public void foo(String[] args) {}

 ...

 // Valid
 foo(new String[] { "a", "b", "c" };

 // Invalid
 foo({"a", "b", "c"});

As for the purpose – the purpose of the first syntax is to allow variable declarations to be more concise… and the purpose of the second syntax is for general-purpose use as an expression. It would be odd to disallow the second syntax for variable declarations, just because the more concise syntax is available.