Are you sure the OP is Perl code? Looks like it might be D.
Code (D 2.065.0 for Win32): 

import std.stdio;

void main () {

    int[int] a = [ 1:0, 3:2, 5:4, ];

    foreach (k, v;  a) {
        writefln("%d => %d", k, v);
        }

    }

[download]
Output: 
C:\@Work\DMD2\learn\PM\nmm_7280>pm1115263_1
1 => 0
3 => 2
5 => 4

[download]
But whether this is Perl, D or something else, I, like others, still don't understand how your desired output of  a[5:0] relates to the given initial data.

Give a man a fish:  <%-(-(-(-<

In reply to Re: array question by AnomalousMonk
in thread array question by nmm_7280

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