Array declaration and initialization in Java. Arrays behave differently, when the position of their subscript indices is changed in their declaration

Question

The following is the obvious and usual array declaration and initialization in Java.

int r[], s[];       //<-------
r=new int[10];
s=new int[10];
<         


        

Answer 1

Look at JLS on Arrays:

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.

and

Brackets are allowed in declarators as a nod to the tradition of C and C++. The general rules for variable declaration, however, permit brackets to appear on both the type and in declarators, so that the local variable declaration:

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

is equivalent to the series of declarations:

float[][][][] f;
float[][][][][] g;
float[][][] h;

So for example:

int []p, q[];

is just

int[] p, q[]

which is in fact

int p[]; int q[][]

The rest are all similar.