compare 2 2Dimensional arrays - Java

Question

Why isn't this true?

int[][] arrayOfSets = {{1,2},{9,10},{1,2},{3,5}};
int[][] test =        {{1,2},{9,10},{1,2},{3,5}};

if(arrayOfSets==test){ //{{1,2},{9,10},{1,2},{3,5}}){
   System.out.println("Exactly the same");
}

The output should be "Exactly the same". or how can I compare 2 variables with 2dimensional arrays?

score 2 · Answer 1 · edited May 23 '17 at 11:49

2

To compare multidimensional arrays, use .deepEquals The link explains why

.deepEquals

And the following link explains why == or .equals doesn't work.

.equals definition

edited May 23 '17 at 11:49

Community

1
1

answered Nov 12 '14 at 16:07

thisismario123

43
1
9

score 1 · Accepted Answer · answered Nov 12 '14 at 15:58

1

You use == thats why failed, it's for identical of object check so use :

boolean check = Arrays.deepEquals(arrayOfSets, test);

answered Nov 12 '14 at 15:58

Fevly Pallar

3,059
2
15
19

score 0 · Answer 3 · answered Nov 12 '14 at 18:05

This does not work because == compares the reference ie you can think of that as memory address..In this case since you are declaring 2 different arrays, their addresses are bound to be different.

One small suggestion since your array doesn't contain consecutive numbers such as {1,2}, {1,3} similarly.... you can instead use objects with 2 instance numbers and put those objects inside an array

compare 2 2Dimensional arrays - Java

3 Answers3