returning an array

How do I return an array?
Is it
return (a[][]);
or is it
return (a);
?

use return a;
You use the backets only when declaring an array (e.g. String a[][] = new String[5][5]) or working with a specific element in an array (e.g. a[1][2] = "test" or String s = a[1][2]).
When in doubt, just try compiling it.

Well, thanks, but I get this errror
when using
return (a);

..........java:74: incompatible types
found : double[][]
required: double
return(a);
^

What are you declaring that you return? You need to do something like this:
public double[][] myMethod() {
double[][] a;
.....
return a;
}
And when you invoke the method:
double[][] b = myMethod();