Beefy Boxes and Bandwidth Generously Provided by pair Networks
"be consistent"
 
PerlMonks  

Re: 1 vs "1"

by Jeff Connelly (Acolyte)
on Sep 13, 2001 at 03:18 UTC ( #112056=note: print w/replies, xml ) Need Help??


in reply to 1 vs "1"

You may be able to exploit the ~ operator, it has deep knowledge of Perl's internals. For example:
$string = "1"; $integer = 1; print ~$string; # Prints an extended character print ~$integer; # Prints 4294967294
Much easier than messing with perlguts. But there's one caveat: using ~ on a string with extended characters results in ASCII characters; that is ~chr(205) is "2". Assuming your definition of "string" does not include extended characters (only ASCII), you should be able to get away with a function like this:
sub is_integer { return (~$_[0] =~ m/^[0-9]+$/) ? 1 : 0; } print "1 ", is_integer(1), "\n"; # 1 ok print "'1' ", is_integer('1'), "\n"; # 0 ok print "chr(205) ", is_integer(chr(205)),"\n"; # 1 not ok
That said, be careful with this power. You don't want to confuse your users. Problems occur when reading data from files or console, as everything read is a string unless explically changed via +0. This also doesn't work for floating point. But sometimes it may have useful uses.

Hope this helps,

Jeff Connelly

Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Node Status?
node history
Node Type: note [id://112056]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others studying the Monastery: (5)
As of 2022-08-11 12:38 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found

    Notices?