how to test a non numeric variable

[bobk5444]

hello, i've checked many sites for examples and am amazed that i can't find a simple example of an if statement to test for an alphanumber value ie: if($key == "a" )

to run this pgm: perl del3.pl delin

delin data is:
a=1
b=2
c=3

thanks for any pointers
ps: java programmer trying to learn PERL!

#!/usr/bin/perl -w
die "Usage: scanmegadata <data file> <site name>\n"
unless @ARGV == 1;

my $megalithFile = $ARGV[0];

open MEGADATA, "<$megalithFile"
or die "Can't open $megalithFile: $!\n";

my ( $key, $value );

my %hash = ();

while ( <MEGADATA> ) {
chop;
( $key, $value ) = split( /=/, $_ );

$hash{$key} = $value;
}

while ( my ($key, $value) = each(%hash) ) {
if($key == "a" )
{
#print "$key => $value\n";
}
}

for my $key ( keys %hash ) {
my $value = $hash{$key};

if($value==1)
{
print "$key => $value\n";
}
}

close MEGADATA;

exit 9;

 

[audiopro]

Welcome to Perl - You'll love it once you are on your feet.
Perl uses a different set of rules from a basic program language. If statements are still used but the more powerful match and substitution operators are the tool to use for finding something.
Do searches for regex and pattern matching in a perl manual and make sure you have plenty of coffee to hand. Get a grip of the basics first as a full blown matching pattern frightens even the best Perl coder.
This is also a good forum where everyone is treated with respect. I have coded it for only a few years but the more experienced on the site collectively know everything. I have tested them on numerous occasions and they haven't failed yet.
Thanks Guys!

Keith

http://www.studiosoft.co.uk

 

[travs69]

== is a numeric comparison
eq is a string comparsion

so
if ($key eq "a")
is what you are looking for.

Read this twice and call me in the morning

http://www.perl.com/doc/manual/html/pod/perlop.html

 

[brigmar]

Although what travs69 said is absolutely correct, you don't need this loop:

[olive][b]while[/b][/olive] [red]([/red] [url=http://perldoc.perl.org/functions/my.html][black][b]my[/b][/black][/url] [red]([/red][blue]$key[/blue],   [blue]$value[/blue][red])[/red] = [url=http://perldoc.perl.org/functions/each.html][black][b]each[/b][/black][/url][red]([/red][blue]%hash[/blue][red])[/red] [red])[/red] [red]{[/red]
    [olive][b]if[/b][/olive][red]([/red][blue]$key[/blue] == [red]"[/red][purple]a[/purple][red]"[/red] [red])[/red]
    [red]{[/red]
       [gray][i]# .. do whatever .. [/i][/gray]
    [red]}[/red]
[red]}[/red]

You just need to :

[olive][b]if[/b][/olive] [url=http://perldoc.perl.org/functions/exists.html][black][b]exists[/b][/black][/url][red]([/red][blue]$hash[/blue][red]{[/red][red]"[/red][purple]a[/purple][red]"[/red][red]}[/red][red])[/red] [red]{[/red]
   [gray][i]# .. do whatever .. [/i][/gray]
[red]}[/red]

 

[bobk5444]

thanks travs!!

going to do some homework now, thanks for the reference!

how a nice weekend+

BobK

 

[bobk5444]

looks good bigmar, thanks, going to try that!

good weekend!

BobK