How do you add to a 2D arraist

Question

I have the following code. I know the star is correct, but I can not add to arraylist

private ArrayList<int[]> action = new ArrayList<int[]>();
action.add(new int[2]);

then i have

action.add({4,8});  // error

Why can't I add {4,8}to the list?

+3

user3328784 Feb 20 '14 at 0:02

2 answers

You can also do it as follows:

int[] b = new int[2];
b[0] = 4;
b[1] = 8;

Then:

action.add(b);

+1

Ashot karakhanyan Feb 20 '14 at 0:17

arshajii · Accepted Answer · 2014-02-20T00:05:22+0000

You need to write it down completely:

action.add(new int[]{4,8});

A simple {...}short-hand only works when initializing an array during declaration:

int[] a = {4,8};  // works

int[] b;
b = {4,8};  // error

See JLS §10.6 for more details .