Questions[ruby]

I'm working with rails, it happens that when I run my project, I get to the point where I only have to have duplicate values ​​inside the arrays, therefore I have to eliminate the NOT repeated values, for example:

array=[2017,2017,2018,2018,2019]

in this case the value 2019 should be eliminated, since it is not repeated

What I have is the following:

    def saca_no_repetido(array)
        for i in 0...array.length
            if(array[i]!=array[i+1] && array[i+1]!=nil)
                array.delete_at(i)
            end
        end
        return array
    end

I was installing the gems with which Metasploit operates, and in the bcrypt library I got this error:

Fetching bcrypt 3.1.13
Installing bcrypt 3.1.13 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

current directory:
/data/data/com.termux/files/usr/lib/ruby/gems/2.6.0/gems/bcrypt-3.1.13/ext/mri
/data/data/com.termux/files/usr/bin/ruby -I
/data/data/com.termux/files/usr/lib/ruby/2.6.0 -r ./siteconf20190627-18317-12zh00w.rb
extconf.rb
creating Makefile

current directory:
/data/data/com.termux/files/usr/lib/ruby/gems/2.6.0/gems/bcrypt-3.1.13/ext/mri
make "DESTDIR=" clean

current directory:
/data/data/com.termux/files/usr/lib/ruby/gems/2.6.0/gems/bcrypt-3.1.13/ext/mri
make "DESTDIR="
compiling bcrypt_ext.c
compiling crypt_blowfish.c
arm-linux-androideabi-clang  -D__SKIP_GNU -I/data/data/com.termux/files/usr/include
-c -o x86.o x86.S
x86.S:202:29: error: expected '%<type>' or "<type>"
.section .note.GNU-stack,"",@progbits
                            ^
make: *** [<builtin>: x86.o] Error 1

make failed, exit code 2

Gem files will remain installed in
/data/data/com.termux/files/usr/lib/ruby/gems/2.6.0/gems/bcrypt-3.1.13 for inspection.
Results logged to
/data/data/com.termux/files/usr/lib/ruby/gems/2.6.0/extensions/arm-linux/2.6.0/bcrypt-3.1.13/gem_make.out

An error occurred while installing bcrypt (3.1.13), and Bundler cannot
continue.
Make sure that `gem install bcrypt -v '3.1.13' --source 'https://rubygems.org/'`
succeeds before bundling.

In Gemfile:
  metasploit-framework was resolved to 5.0.33, which depends on
    bcrypt

I already tried with gem install bcrypt -v 3.1.13and installing ruby-dev, rvm, json, build-essential, but nothing. They have already asked this same question, but the answers are not my solution. Thanks for answering. Best regards.

It turns out that I need to know how many words a text file has, I have already opened it correctly and tried the method length, but it gives me the number of lines in the file.

I tried to make a gsubto the variable that stores the file but it throws me an error.

I thought I'd try count, but I'm still seeing how it's done.

I understand that you define_methodcreate a method dynamically, but... in what cases would you use it?

What is the 'advantage' or what is different in use, over creating a simple method with def?

Please don't cite memory references or pass links to the official documentation, because that doesn't exactly say what I'm asking.

Good afternoon Community, I come with this Ruby & Rails problem. I am a bit new to the language and this error has me dismayed,

I get the error in the route app/views/bienvenida/index.html.haml:20assuming that the number is the line of code, this is what I have in index:

#hello.top-header
  #top.callbacks_container
    %ul#slider4.rslides
      %li
        = image_tag("slide.jpg", :alt => "")
      .caption.text-center
        **.slide-text-info**
          %h1 ! Bienvenidos ¡
          .slide-text-info-btns
          %li
            %a{:href => ""}
              = image_tag("slide.jpg", :alt => "")
              .caption.text-center
                .slide-text-info
                  %h1 Conoce lo más destacado
                  .slide-text-info-btns
          %li
            = image_tag("slide.jpg", :alt => "")
              .caption.text-center
                .slide-text-info
                  %h1 ¿Aun no estas dentro?
                  %a{:href => ""}
                    %h2 ! Unete ¡
                  .slide-text-info-btns
          .clear

What is in bold is line 20 of my code.

To add more information about the project this is what I have in Application.hmtl.haml:

!!!5
%html
  %head
    %title HOW TO!
    = csrf_meta_tags

    %meta{:content => "width=device-width, initial-scale=1", :name => "viewport"}
    %meta{:content => "text/html; charset=iso-8859-1", "http-equiv" => "Content-Type"}

    = stylesheet_link_tag "application", :media => "all"

    = javascript_include_tag "application"
    = javascript_include_tag "jquery.cslider"
    = javascript_include_tag "jquery.flexisel"
    = javascript_include_tag "jquery.min"
    = javascript_include_tag "modernizr.custom.28468"
    = javascript_include_tag "owl.carousel"
    = javascript_include_tag "responsive-nav"
    = javascript_include_tag "responsiveslides.min"

  :javascript
    addEventListener("load", function() { 
      setTimeout(hideURLbar, 0); }, false); 
      function hideURLbar(){ window.scrollTo(0,1); 
    }

  :javascript
    $(function() {
      var pull = $('#pull');
      menu = $('nav ul');
      menuHeight = menu.height();

      $(pull).on('click', function(e) {
        e.preventDefault();
        menu.slideToggle();
      });

      $(window).resize(function(){
        var w = $(window).width();

        if(w > 320 && menu.is(':hidden')) {
          menu.removeAttr('style');
        }
      });
    });

  :javascript
    (function ($) {
      $("#slider4").responsiveSlides({
        auto: true,
        pager: true,
        nav: true,
        speed: 500,
        namespace: "callbacks",
        before: function () {
          $('.events').append("before event fired.");
        },
        after: function () {
          $('.events').append("after event fired.");
        }
      }(jQuery));
    });

  :javascript
    $(function() {
      $('#da-slider').cslider({
        autoplay    : true,
        bgincrement : 450
      });
    });

  :javascript
    $(function() {
      $('#da-slider1').cslider({
        autoplay    : true,
        bgincrement : 450
      });
    });

  %body
    = yield