How to split array values into to separate arrays in perl

Question

I have an array that stores lat/long together. For example:

@values[0] = "-0.709999984318709,60.690000003554324"

I am trying to separate this into two arrays, @lat and @long, based on the comma.

How can I do this?

Thanks

Is the array element actually a string with a comma in the middle, or a reference to an array with 2 elements? — user2404501
– user2404501, Commented Jun 4, 2013 at 9:02
@WumpusQ.Wumbley its a string with a comma in it. I created it by spliting a string into an array based on spaces. — whatahitson
– whatahitson, Commented Jun 4, 2013 at 9:05
You knew that you wanted to split. So try perldoc -f split. — devnull
– devnull, Commented Jun 4, 2013 at 9:20

TLP · Accepted Answer · 2013-06-04 09:37:35Z

6

I assume you want to keep each latitude and longitude value together, in which case transforming your array into a two-dimensional array would be appropriate:

my @latlong = map { [ split /,/, $_, 2 ] } @values

I used the full notation of split here in order to invoke the LIMIT condition of 2 fields. It may not matter for this data, but it may matter if the conditions change.

The code of the map statement first splits each element of @values into two, puts the resulting list of 2 into an anonymous array [ ... ], which is then inserted into the new array. The resulting array looks like this when printed with Data::Dumper:

$VAR1 = [
          [
            '-0.709999984318709',
            '60.690000003554324'
          ]
        ];

answered Jun 4, 2013 at 9:37

TLP

68.2k10 gold badges97 silver badges156 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

RichM · Accepted Answer · 2013-06-04 09:06:41Z

4

First off, it's better to write $values[0] to reference the array element.

The split command will help you here, assuming the comma is consistent:

foreach (@values) {
  my @separated = split(',', $_);
  push @lat, $separated[0];
  push @long, $separated[1];
}

There's a number of ways this can be done, but I've done it in a manner that should show how the arrays are handled.

answered Jun 4, 2013 at 9:06

RichM

2721 gold badge2 silver badges14 bronze badges

4 Comments

whatahitson Over a year ago

thanks. this works but seems to do something odd with my loop print "$name: @values\n\n"; would return each area name and its coordinates, one by one. but print "$name: @long\n\n"; returns all the longitudes for all of the areas, repeatedly for every name. I think I put the code in the right place, but cant think of why this.

TLP Over a year ago

@whatahitson What $name variable are you talking about? You can't just invent new things to put into your question.

whatahitson Over a year ago

@TLP $name is the name of each map that I have coordinates for. I tried to keep my question simple by only including the relevent part of my code. Is it better form to include all of the code in my script?

TLP Over a year ago

@whatahitson If you want recommendations on a data structure, yes.

Collectives™ on Stack Overflow

How to split array values into to separate arrays in perl

2 Answers 2

Comments

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related