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How to set variables to 1.

cuboidgraphix
User

Feb 23, 2012, 1:37 PM

Post #1 of 5 (1034 views)

How to set variables to 1.	Can't Post

Hi guys,
Is there a simpler way to set variables to 1? Rather than having something like this...

my $a = 1;
my $b = 1;
my $c = 1;
my $d = 1;
my $e = 1;
my $f = 1;
my $g = 1;
my $h = 1;
my $i = 1;

Looking for a simpler method of setting 1 to all those variables. Thanks for any help.

BillKSmith
Veteran

Feb 23, 2012, 8:04 PM

Post #2 of 5 (1019 views)

Re: [cuboidgraphix] How to set variables to 1. [In reply to]	Can't Post

Code

my ($a, $b, $c, $d, $e, $f, $g, $h, $i) = (1)x9;

You probably should not be using this many variables. Consider a hash.

Code

my %hash = ( 
    a => 1, 
    b => 1, 
    c => 1, 
    d => 1, 
    e => 1, 
    f => 1, 
    g => 1, 
    h => 1, 
    i => 1, 
    );

Good Luck,
Bill

naven8
Novice

Feb 24, 2012, 6:33 AM

Post #3 of 5 (1013 views)

Re: [BillKSmith] How to set variables to 1. [In reply to]	Can't Post

Is there any way to change default value of variable?

Thanks

rovf
Veteran

Feb 24, 2012, 7:45 AM

Post #4 of 5 (1011 views)

Re: [naven8] How to set variables to 1. [In reply to]	Can't Post

Fortunately not! This would break immediately all library code....

BillKSmith
Veteran

Feb 24, 2012, 11:34 AM

Post #5 of 5 (1007 views)

Re: [naven8] How to set variables to 1. [In reply to]	Can't Post

When a variable is declared, it is assigned a "value" of undef. When that variable is defined, it is assigned the specified value. You would not want to change this behavior.

When we define a variable, we can specify a default value to use if a value is not avaiable from the usual source. (e.g. Specify an input file name to use if the user does not specify one on the command line.)

Code

 my $file_name = $ARGV[0] || 'default_input.txt';

Refer to the chapter "Establishing a Default Value" in the book "Perl Cookbook" for a detailed discussion of this topic.
Good Luck,
Bill

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