CODEWITHSUNDEEP
arraysperlsortingmultidimensional-array
cjhutton
cjhutton

Reputation: 91

Sort a row of a 2D array in perl

Say I have a 2D array in perl

[2, 4, 6, 1, 3, 2]            # $i = 0
[5, 2, 4, 2, 1]               # $i = 1
[8, 2, 3, 5, 7, 1, 3, 5]      # $i = 2
[2, 1]                        # $i = 3

How can I sort one row so they remain in the same order?

such as:

[2, 4, 6, 1, 3, 2]
[1, 2, 2, 4, 5]                  # sorted row
[8, 2, 3, 5, 7, 1, 3, 5]
[2, 1]

I tried an easy route to sort the $i row,

@array[$i] = sort(@array[$i]);

It does nothing to change the order of the array, my other attempts have deleted the array row all together.

Other 2D sorting questions I can find are for reordering rows/sorting columns.

I'm sure the answer is very easy.

Upvotes: 0

Views: 367

Answers (1)

Sobrique
Sobrique

Reputation: 53488

OK, the thing you need to know is - that an array of arrays in perl, is implemented as an array of array references.

So - $array[$i] - is a reference to an array.

So you can simply:

 @{$array[$i]} = sort @{$array[$i]};

Although note by default, sort does alphanumeric, rather than just numeric.

So you might want:

 @{$array[$i]} = sort { $a <=> $b } @{$array[$i]};

Or if you want to do the whole lot:

@$_ = sort {$a<=>$b} @$_ for @array;

Upvotes: 6

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