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Difference between revisions of "Perl/Basics/User Defined Functions"

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(Created page with "A function is defined by the programmer to create re-usable code. In our example, we will make an is_integer function that returns either 1 or undef depending on whether the sca...")
 
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Latest revision as of 03:18, 16 July 2012

A function is defined by the programmer to create re-usable code. In our example, we will make an is_integer function that returns either 1 or undef depending on whether the scalar passed is an integer or not. 

sub is_integer {
    my $scalar = shift;
    return 1 if (int($scalar) == $scalar);
    return undef;
}

Usage: 

 
print "This scalar is an integer.\n" if (defined is_integer($scalar)) else print "This is not an integer.\n";
 
Perl's return function can return multiple data types and variables, i.e.: 
return($scalar,@array);
To use this type of function: 
my ($scalar,@array) = function();
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