📘 Variables in Perl 6: Sigils

Perl 6 uses sigils to mark variables. The sigils are partially compatible with the Perl 5 syntax. For instance, scalars, lists and hashes use, respectively, the $, @, and % sigils. my $scalar = 42; say $scalar; It’s not a surprise that the code prints 42. Consider the following fragment, which also gives a predictable … Continue reading “📘 Variables in Perl 6: Sigils”

📘 Bool in Perl 6

The usage of the Bool variables is straightforward although there are some details about which you might want to know. The Bool type is a built-in enumeration and provides two values: True and False (or, in a full form, Bool::True and Bool::False). It is permissible to increment or decrement the Boolean variables: my $b = … Continue reading “📘 Bool in Perl 6”

📘 Str type in Perl 6

Str is no doubt a string. In Perl 6, there are methods to manipulate strings. Again, you call them as methods on objects. my $str = “My string”; say $str.lc; # my string say $str.uc; # MY STRING say $str.index(‘t’); # 4 Let us now get the length of a string. The naïve attempt to … Continue reading “📘 Str type in Perl 6”

📘 Hash in Perl 6

Hashes provide a few methods with clear semantics, for instance: my %hash = Language => ‘Perl’, Version => 6; say %hash.elems;  # number of pairs in the hash say %hash.keys;   # the list of the keys say %hash.values; # the list of the values Here’s the output:  2 (Version Language) (6 Perl) It is possible … Continue reading “📘 Hash in Perl 6”

📘 Prefix operator + in Perl 6

+ is the unary plus operator, which casts its operand to the numerical context. The action is equivalent to the call of the Numeric method. my Str $price = ‘4’ ~ ‘2’; my Int $amount = +$price; say $amount;        # 42 say $price.Numeric; # 42 We will see one of the important use cases of … Continue reading “📘 Prefix operator + in Perl 6”

📘 Method postfix operator .+ in Perl 6

.+method makes an attempt to call all the methods with the given name on an object. This may be used, for example, when an instance is a part of the hierarchy of objects and its parent also has a method with the same name. More on the classes and class hierarchy in Chapter 4. class … Continue reading “📘 Method postfix operator .+ in Perl 6”

📘 Prefix operator ++ in Perl 6

++ is a prefix operator of increment. First, an increment is done, and then a new value is returned. my $x = 41; say ++$x; # 42 The increment operation is not limited to working only with numbers. It can also handle strings. my $a = ‘a’; say ++$a; # b A practical example is … Continue reading “📘 Prefix operator ++ in Perl 6”