Re: When does '123' become the number 123.0?

[radiantmatrix]

I'm reading a comma-separated-value ascii text file containing numerical data, e.g. "123,234,456" on each line.

I'm using 'split' to separate the fields of each line

Don't do that. Use Text::CSV_XS. CSV files will bite you if you're not careful.

Is it the string "123" or the number 123.0? And does it make any difference to the perl programmer?

It's a scalar. Don't worry about how it's stored under the hood, it will be a string or an integer or a float when you need it to be one of those things.

Under the hood, since you're using split, you'll be getting strings. But:

my $line = '123,456,789';
my ($val) = split(',' , $line);  # $val is the string '123'
$val += 2;                       # $val is now the integer 125
$val /= 2;                       # $val is now the float 62.5
print "I ended up with $val"     # $val is treated as the string '62.5
+'

The whole point of Perl's weak typing is that you don't have to worry about this sort of thing. If you want to validate that your scalar contains a certain type of data (not under the hood, mind you), check out Data::Validate.