wantarray is yet another reason why perl is a great programming language.
You can use wantarray to have change what your function returns based
upon the context in which it was called.
For example, say you have a function called unique() which
takes an @array as its argument. You can use wantarray
to have unique() return a list of unique elements
from @array or the number of unique elements
depending upon context.
sub unique {
my @array = @_;
my %temp = map { $_ => 1 } @array;
if ( wantarray() ) {
return sort( keys( %temp ) ); # the unique elements
}
else {
return scalar( keys( %temp ) ); # the number of unique elements
}
}
You can now call unique() as follows:
my @unique_array = unique( @array ); # get a sorted unique list
my $unique_number = unique( @array ); # get the number of elements.
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