Print unique digits from a given integer number.
The task is easily solved if an integer is immediately converted to a string.
my $number = prompt('Enter number> ');
say $number.comb.unique.sort.join(', ');
The combmethod, called with no arguments, splits the string into separate characters. The method is defined in the Str class; thus, the $number is converted to the string first. The same may be explicitly written as:
$number.Str.comb
Notice that in the case of using $number.split(''), empty elements are added to the beginning and the end of the array.
At this moment, an initial number resides in an array, each element of which is a digit from the $number.
Taking unique elements of an array does not require any manual programming in Perl 6, as the Array class contains a special method for that:
$number.comb.unique
Finally, to make the result look better, the array of unique digits is sorted and printed as a comma-separated list:
$number.comb.unique.sort.join(', ')
Instead of calling sayas a stand-alone function, it may be called as a method on the resulting string:
$number.comb.unique.sort.join(', ').say;