Confused with Array in Java - arrays

Question

Could someone please answer why the output of this code is 225? Why not 222 since you are changing a?
When you look at code no.2 a when a is passed to test(), it completely changed. My question is why is that 'a' in number 1 did not change when passed to test() while 'a' in number 2 changed?
I'm a beginner at Java.
1.
public class Array1
{
static void test(int[] a)
{
int[] b = new int[2];
a = b;
System.out.print(b.length);
System.out.print(a.length);
}
public static void main(String[] args)
{
int[] a = new int[5];
test(a);
System.out.print(a.length);
}
}
2.
public class Array2
{
static void test(int[] a) {
int[] b = new int[2];
for(int i =0; i< a.length; i++)
{
a[i]=1;
}
}
public static void main(String[] args)
{
int[] a = new int[5];
test(a);
for(int i =0; i< a.length; i++)
{
System.out.print(a[i]);
}
}

Answer 1

Let's see what happens step by step in case 1
main: int[] a = new int[5]; : declares a ref variable in main pointing to a array of 5 ints
main: test(a); : calls test with a reference to the original array
test: static void test(int[] a) { : declares a ref variable a to hold a ref to the caller array => a in test is another reference to the original array
test: int[] b = new int[2]; : declares a ref variable in test to a new array of 2 ints
test: a = b; : makes the ref variable a in test point to the new array => the original array is unchanged as is the a variable in main
remaining of the output is now normal.
Now case 2:
main: int[] a = new int[5]; : declares a ref variable in main pointing to a array of 5 ints
main: test(a); : calls test with a reference to the original array
test: static void test(int[] a) { : declares a ref variable a to hold a ref to the caller array => a in test is another reference to the original array
test: int[] b = new int[2]; : declares a ref variable in test to a new array of 2 ints...
test: a[i] = 1; : as a is a reference to the original array, you are changing values in the original array.
output should now be clear.

Answer 2

In the first code you are getting 225:
following are the reasons:
let address of a be - aa111
let address of b be - bb111
1) you are changing the address of a in the test method so in test method a address will become bb111.
2)but you are not returning the a to the main method it restores to the original address of a which is aa111.
3) you will get 222 if you return a from test method.
here is the code for that
public class Array1
{
static int[] test(int[] a)
{
int[] b = new int[2];
a = b;
System.out.print(b.length);
System.out.print(a.length);
return a;
}
public static void main(String[] args)
{
int[] a = new int[5];
a = test(a);
System.out.print(a.length);
}
}