Example of unary operator overloading in Ruby

We all know that the expression operator has only one input value. This is common in C and Java. Today we will discuss the unary operator overloading in Ruby.
Unary operators include: + -*! & Etc. To avoid confusion with the value +-, to overload the unary operator, add an @ operator to the end.

1. Example of a simple unary operator overload:-@ Operator
We use the String class as an example. The String is not defined by default-OPERATOR:

The Code is as follows:
1.9.3p125: 027> a = "Hello"

=> "Hello"

1.9.3p125: 028>-

NoMethodError: undefined method '-@' for "Hello": String

From (irb): 28

From ~ /. Rvm/rubies/ruby-1.9.3-p125/bin/irb: 16: in''

1.9.3p125: 029>

We use the Open Class method (Open Class can be referred to) to add the unary operation to the object of String type:
The Code is as follows:

1.9.3p125: 029> def a.-@; downcase; end;

1.9.3p125: 036>
=> "Hello"
1.9.3p125: 037>-
=> "Hello"
1.9.3p125: 038>

From the code above, we have added the-operator to object.

2. Other operators: + @,~, !
We use the Open Class Feature again to add the method to the String Class:
The Code is as follows:

#! /Usr/local/ruby/bin/ruby

Class String

Def -@

Downcase

End

Def + @

Upcase

End

Def ~

# Do a ROT13 transformation-http://en.wikipedia.org/wiki/ROT13

Tr 'a-Za-Z', 'N'-ZA-Mn-za-m'

End

Def to_proc

Proc. new {self}

End

Def to_a

[Self. reverse]

End

End

Str = "Teketa's Blog is GREAT"

Puts "-# {str }=#{-str }"

Puts "+ # {str }=#{+ str }"

Puts "~ # {Str }= #{~ Str }"

Puts "# {str}. to_a = # {str. to_a }"

Puts % w {a, B}. map & str

Puts * str

The running result of the above Code:

The Code is as follows:
-Teketa's Blog is GREAT = teketa's blog is great

+ Teketa's Blog is GREAT = TEKETA's BLOG IS GREAT

~ Teketa's Blog is GREAT = Grxrgn 'f Oybt vf TERNG

Teketa's Blog is GREAT. to_a = ["TAERG si golB s 'ateket"]

Teketa's Blog is GREAT

Teketa's Blog is GREAT

TAERG si golB s 'ateket

We noticed that the * and & operators are reloaded through to_a and to_proc. In Ruby, the * and & must be reloaded through the to_a and to_proc methods.