Primitive Array initialization without value?

Question

I just found a random code snippet:

int[] i = new int[]{0,};

How is this even possible?

Primitive types can't be null...

I just wonder what this is creating...

0 is not null, is 0 Should create an array of size 1 with value 0 — Alessandro Dal Gobbo, May 14 '16 at 13:10

Vikrant Kashyap · Accepted Answer · 2016-05-14T13:23:20.123

2

Here new int[] will create an array and initialize with array elements {1}.

new int[]{1,}; // Create an array of int of size 1 with value 1 as a first element

if you print the length of int[] i. Size will be print 1. because last comma is ignored if no further element found.

System.out.println(i.length); // it will print 1

Here i is a reference variable which holds the array Onject. while new int[] will only responsible for creating Array.

Thank You

edited May 14 '16 at 13:23

answered May 14 '16 at 13:10

Vikrant Kashyap

But why couldn't I just simple do `new int[]{0}` or `new int[]{1}`? – RoiEX May 14 '16 at 13:11
you are doing the same here ? then what exactly your question is ?? @RoiEX – Vikrant Kashyap May 14 '16 at 13:14
Whats the difference between `new int[]{0}` and `new int[]{0,}` ? – RoiEX May 14 '16 at 13:15
second statement `new int [] (0,)` will automatically ignore the last comma expression if there is no such element present further in the list. @RoiEX – Vikrant Kashyap May 14 '16 at 13:21

Sleiman Jneidi · Answer 2 · 2016-05-14T13:29:47.210

2

This would create an array of length 1 which is equivalent to

int[] i = new int[]{0};

The last comma will be ignored as specified in JLS §10.6

A trailing comma may appear after the last expression in an array initializer and is ignored.

edited May 14 '16 at 13:29

answered May 14 '16 at 13:18

Sleiman Jneidi

2 Answers2