小编Bib*_*rma的帖子

Ruby Hash和ActiveSupport有什么区别HashWithIndifferentAccess？动态哈希哪个最好？

调用super和调用super()有什么区别？如果传递给子方法的参数与父期望的不匹配,那么哪个是最好的.

我是Ruby on Rails的新手,我浏览了这些文章.

• Ruby中的设计模式:Observer,Singleton
• Ruby中的设计模式

但我无法理解设计模式和设计原则之间的实际区别.有人可以解释这个区别吗？

如果数组列表太大,为什么以下递归代码会导致堆栈溢出？我该如何解决这个问题仍然保留递归模式？

var list = readHugeList();

var nextListItem = function() {
    var item = list.pop();

    if (item) {
        // process the list item...
        nextListItem();
    }
};

我正在尝试在我的MAC OS X Yosemite上重新安装mysql.为此,我按照下面的说明进行操作

sudo rm /usr/local/mysql
sudo rm -rf /usr/local/mysql*
sudo rm -rf /Library/StartupItems/MySQLCOM
sudo rm -rf /Library/PreferencePanes/MySQL*
vim /etc/hostconfig and removed the line MYSQLCOM=-YES-
rm -rf ~/Library/PreferencePanes/MySQL*
sudo rm -rf /Library/Receipts/mysql*
sudo rm -rf /Library/Receipts/MySQL*
sudo rm -rf /var/db/receipts/com.mysql.*

我也试过了

brew uninstall mysql

在此之后我使用homebrew using命令安装了mysql brew install mysql.安装后,当我尝试运行mysql -u root它时抛出以下错误

ERROR 1045(28000):用户'root'@'localhost'拒绝访问(使用密码:否)

我没有为mysql设置密码.我不知道出了什么问题.任何建议都将不胜感激.谢谢

我正在使用dropzone.js在rails上的ruby上传图像.这是我的HTML代码

<div class="row">
  <div class="col-md-12" id="drop-zone-container">
    <%= form_tag '/settlement_proofs', method: :post, class: 'dropzone form', id: 'media-dropzone' do %>
        <div class="fallback">
          <%= file_field_tag 'attachment', multiple: true%>
        </div>
    <% end %>
  </div>
</div>

我将dropzone初始化为

$("#media-dropzone").dropzone({
    acceptedFiles: pg.constants.ACCEPTED_FORMAT,
    maxFilesize: pg.constants.ATTACHMENT_MAX_FILE_SIZE, //In MB
    maxFiles: pg.constants.ATTACHMENT_MAX_SIZE,
    addRemoveLinks: true,
    removedfile: function (file) {
        if (file.xhr.responseText.length > 0) {
            var fileId = JSON.parse(file.xhr.responseText).id;
            $.ajax({
                url: pg.constants.url.SETTLEMENT_BASE_URL + fileId,
                method: 'DELETE',
                dataType: "json",
                success: function (result) {
                    $('#uploaded_attachment').val($("#uploaded_attachment").val().replace(result.id + ',', ""));
                    $('#settlement_proof_status span').fadeOut(0);
                    var _ref;
                    return …

我是Ruby的新手.我正在学习ruby中的抽象原理.我理解过程抽象是隐藏用户的实现细节,或者只是专注于基本要素而忽略细节.

我关心的是如何实现它

1)这是一个简单的函数调用就像这样

# function to sort array
# @params array[Array] to be sort

def my_sort(array)
  return array if array.size <= 1

  swapped = false
  while !swapped
    swapped = false
    0.upto(array.size-2) do |i|
      if array[i] > array[i+1]
        array[i], array[i+1] = array[i+1], array[i]
        swapped = true
      end
    end
  end

  array
end

并且这样打电话

sorted_array = my_sort([12,34,123,43,90,1])

2)数据抽象与封装有何不同

据我所知,Data Abstraction只是隐藏了其他类的一些成员数据.

安装ruby版本1.9.3-p551时出现以下错误.

ruby-1.9.3-p551 - #removing src/ruby-1.9.3-p551 - please wait
Searching for binary rubies, this might take some time.
No binary rubies available for: osx/10.10/x86_64/ruby-1.9.3-p551.
Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
Checking requirements for osx.
Certificates in '/usr/local/etc/openssl/cert.pem' are already up to date.
Requirements installation successful.
Installing Ruby from source to: /Users/brijesh/.rvm/rubies/ruby-1.9.3-p551, this may take a while depending on your cpu(s)...
ruby-1.9.3-p551 - #downloading ruby-1.9.3-p551, this may take a while depending on your …

样板和模板有什么区别？我以为是同一回事。你为什么不只说“模板”？

我正在尝试在 Cent-OS 中部署 Rails 应用程序。当我运行curl -L get.rvm.io | bash -s stable设置 ruby​​ 环境时。我得到以下输出

[root@186-aven-vps marketeurepo]# curl -L get.rvm.io | bash -s stable
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   184  100   184    0     0    581      0 --:--:-- --:--:-- --:--:--   580
100 22721  100 22721    0     0  35092      0 --:--:-- --:--:-- --:--:-- 35092

ERROR: Could not find 'which' command, make sure it's available first before continuing installation. …