Java array assignment multiple values keeping the initial array

Question

Is there a way in Java to assign multiple values to an Array in one statment then later you can still be able to append to the same array other values?

e.g. Having a String array defined already with length of 4

String[] kids = new String[4];

I would like to assign multiple values (2 values for example) to the array in one statment; maybe something close to the array init

kids = {"X", "Y"};

or the array redefinition

kids = new String[] {"X", "Y"};

but without loosing the initial array as later I will need to add to it other values e.g.

if(newKid) {
    kids[3] = "Z";
}

or there is no way to achieve this and have to assign values one by one

kids[0] = "X";
kids[1] = "Y";
if(newKid) {
    kids[3] = "Z";
}

Answer 1

You will need to copy the array with the initialized values into a larger array:

String[] kids = Arrays.copyOf(new String[]{ "x", "y" }, 4);
kids[2] = "z";

Alternative copy solution:

String[] kids = new String[4];
System.arraycopy(new String[]{"x", "y"}, 0, kids, 0, 2);
kids[2] = "z";

Alternatively you could have empty Strings as placeholders:

String[] test ={ "x", "y", "", "" };
test[2] = "z";

Or you could use a List<String>:

List<String> kids = new ArrayList<>(4);
Collections.addAll(kids, "x", "y");
kids.add("z");

Alternative List<String> solution:

List<String> kids = new ArrayList<>(Arrays.asList("x", "y"));
kids.add("z");

Answer 2

It's solved here Resize an Array while keeping current elements in Java?

Btw, you can use Lists so you won't need to resize

Answer 3

You can do the following:

String[] kids = new String[4];
System.arraycopy(new String[] {"X", "Y"}, 0, kids, 0, 2);