override of a 2D array cells in bash

Question

I tried the following 2D array set in bash:

$ a[0,0]=a0
$ a[1,0]=a1
$ echo ${a[0,0]}
a1

I expect to get a0, What I m missing?

I'm not 100% sure of this but I think that `0,0` and `1,0` are being evaluated inside an arithmetic context, so you get the same result as `$((1,0))` and `$((0,0))` i.e. the first digit is evaluated and discarded, leaving you with `0` in both cases. I don't know where you got the idea that multi-dimensional arrays are supported in the first place though. — Tom Fenech, Nov 24 '16 at 09:33
Bash **ONLY** provides one-dimensional indexed and associative array variables. Although there're some tricky ways to simulate multi-dimensional arrays, they are not a good solution. If you have the chance, you'd better move to other scripting languages such as Perl, Pyhton or even some versions of Ksh where multi-dimensional arrays are supported. — MarcM, Nov 24 '16 at 09:38

score 1 · Answer 1 · edited May 23 '17 at 11:53

1

Bash has no support for multi-dimensional arrays, but you can simulate 2d arrays as discussed in this answer

edited May 23 '17 at 11:53

Community

answered Nov 24 '16 at 09:12

nradk

score 0 · Accepted Answer · answered Nov 24 '16 at 09:22

0

The answer is to add

declare -A a

answered Nov 24 '16 at 09:22

MOHAMED

2

Declaring a variable '-a' (array) doesn't provide multi-dimensional support. Bash ONLY supports one-dimensional arrays. Although there're some tricky ways to simulate multi-dimensional arrays, they are not a good solution. – MarcM Nov 24 '16 at 09:35
@MarcM it works for me – MOHAMED Nov 24 '16 at 09:39
@MOHAMED: this is not really a 2D array - it's just a hack which simulates 2D arrays using hashes - see [this answer](http://stackoverflow.com/a/16487733/253056) for a full explanation. – Paul R Dec 01 '16 at 17:21

2 Answers2