sort associative array in awk - help?

Question

Hi all, I have an associative array in awk that gets populated like this...

chr_count[$3]++

When I try to print my chr_counts I use this:

for (i in chr_count) {
    print i,":",chr_count[i];
}

But not surprisingly, the order of i is not sorted in any way. Is there an easy way to iterate over the sorted "keys" of chr_count?

Answer 1

This is taken directly from the documentation:

 populate the array data
 # copy indices
 j = 1
 for (i in data) {
     ind[j] = i    # index value becomes element value
     j++
 }
 n = asort(ind)    # index values are now sorted
 for (i = 1; i <= n; i++) {
     do something with ind[i]           Work with sorted indices directly
     ...
     do something with data[ind[i]]     Access original array via sorted indices
 }

Answer 2

Instead of asort, use asorti(source, destination) which sorts the indices into a new array and you won't have to copy the array.

Then you can use the destination array as pointers into the source array.