Zubinix has asked for the wisdom of the Perl Monks concerning the following question:

Oh wise monks How can I get code like this: 
my $range = "1..10"
for my $x ($range)
{
  print "$x\n";
}

[download]
to print out the numbers from 1 to 10? That is specify a range to use in the for loop programmatically? Thanks

Replies are listed 'Best First'.
Re: Specifying a range through a variable
by dragonchild (Archbishop) on Sep 19, 2008 at 02:16 UTC 
    my @range = 1..10;
for my $x (@range)
{
  print "$x\n";
}

    [download]
    My criteria for good software:
    1. Does it work?
    2. Can someone else come in, make a change, and be reasonably certain no bugs were introduced?
[reply]
[d/l]
      what if the range is passed in as a string? How to do convert the string "1..10" to mean the range 1 through to 10?
[reply]
        How to do convert the string "1..10" to mean the range 1 through to 10

        A bit kludgey: 
        use warnings;
my $range = "1..10";
my @wanted = range($range);
print "@wanted\n";

sub range {
    my @t = split /\.\./, $_[0];
    return ($t[0] .. $t[1]);
}

        [download]
        Update: To return first and last values, obviously: 
        sub range {
    my @t = split /\.\./, $_[0];
    return ($t[0], $t[1]);
}

        [download]
        Cheers,
        Rob
[reply]
[d/l]
[select]

        Use eval, if you must. 

        my $range = '1..10';
for my $x ( eval $range ) {
    print "$x\n";
}

        [download]

        Beware, however, that input validation is very important here. The string you pass into eval can be any Perl code, and it will do whatever that code does.

[reply]
[d/l]

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