我想知道在Rails中将带负号的字符串转换为数字的方便函数是什么.例如-1005.32
当我使用该.to_f方法时,数字变为1005负号,小数部分被忽略.
我可以生成几行代码,但是我想知道是否有一个很好的干净Rubyesque方式.如果我没有明确的,就是我正在寻找的是一个数组的方法,如果给定的(说),这将返回true [3,3,3,3,3]或["rabbits","rabbits","rabbits"]但将返回false用[1,2,3,4,5]或["rabbits","rabbits","hares"].
谢谢
我不知道我是只是在寻找错误的东西或者是什么,但是有一种简单的方法来评估范围并使用(2..100)语法检查整数是否在该范围内.
例如,如果我的整数x = 100和我的范围是(0..200),我想要评估为真,我只是在寻找简单,简洁的红宝石方式.
在其他语言regexp中,您可以使用// g进行全局匹配.
但是,在Ruby中:
"hello hello".match /(hello)/
只捕获一个你好
我如何捕获所有你好？
我已成功配置RVM以使用Ruby 1.9.2,一切都很好.但是,当我尝试使用sudo它运行Ruby时,它说无法找到RVM或Ruby:
$ ruby -v
ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-linux]
$ sudo ruby -v
[sudo] password for administrator:
sudo: ruby: command not found
这是正确的行为还是我的RVM配置错误？也许我应该使用系统范围的安装？
我已经尝试阅读各种博客文章,试图解释alias_method_chain以及使用它的原因而不是使用它.特别是,我注意到:
http://weblog.rubyonrails.org/2006/4/26/new-in-rails-module-alias_method_chain
和
http://yehudakatz.com/2009/03/06/alias_method_chain-in-models/
我仍然没有看到alias_method_chain的任何实际用途.任何人都可以解释一些事情.
1 - 它还在使用吗？
2 - 你何时会使用alias_method_chain？为什么？
我将 CocoaPods 更新到版本1.13.0. 现在，当我运行时pod install，它会抛出以下错误：
conversions.rb:108:in '<class:Array>': undefined method 'deprecator' for ActiveSupport:Module (NoMethodError)
我该如何修复它？
这是完整的错误：
bundler: failed to load command: pod (/opt/homebrew/opt/bin/rbenv/versions/3.2.2/bin/pod)
/opt/homebrew/opt/bin/rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/activesupport-7.1.0/lib/active_support/core_ext/array/conversions.rb:108:in `<class:Array>': undefined method `deprecator' for ActiveSupport:Module (NoMethodError)
deprecate to_default_s: :to_s, deprecator: ActiveSupport.deprecator
^^^^^^^^^^^
Did you mean? deprecate_constant
from /opt/homebrew/opt/bin/rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/activesupport-7.1.0/lib/active_support/core_ext/array/conversions.rb:8:in `<top (required)>'
from <internal:/opt/homebrew/opt/bin/rbenv/versions/3.2.2/lib/ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
from <internal:/opt/homebrew/opt/bin/rbenv/versions/3.2.2/lib/ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
from /opt/homebrew/opt/bin/rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/cocoapods-1.13.0/lib/cocoapods.rb:9:in `<top (required)>'
from <internal:/opt/homebrew/opt/bin/rbenv/versions/3.2.2/lib/ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
from <internal:/opt/homebrew/opt/bin/rbenv/versions/3.2.2/lib/ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
from /opt/homebrew/opt/bin/rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/cocoapods-1.13.0/bin/pod:36:in `<top (required)>'
from /opt/homebrew/opt/bin/rbenv/versions/3.2.2/bin/pod:25:in `load'
from /opt/homebrew/opt/bin/rbenv/versions/3.2.2/bin/pod:25:in `<top (required)>'
from /opt/homebrew/opt/bin/rbenv/versions/3.2.2/lib/ruby/3.2.0/bundler/cli/exec.rb:58:in `load'
from /opt/homebrew/opt/bin/rbenv/versions/3.2.2/lib/ruby/3.2.0/bundler/cli/exec.rb:58:in …这段代码中的超级是什么？
def initialize options = {}, &block
@filter = options.delete(:filter) || 1
super
end
据我所知,这就像递归调用函数一样,对吧？
假设以下ruby代码:
bank.branches do |branch|
branch.employees.each do |employee|
NEXT BRANCH if employee.name = "John Doe"
end
end
NEXT BRANCH当然是伪代码.有没有一种方法可以打破一个父循环,例如在Perl中这样做的方式(通过使用循环标签)？
提前致谢.
安装rvm,更新.gmrc文件,更新rubygems并运行后gem install rails -v ">=3.1.0rc",我现在似乎已经完全搞乱了:
$ rails -v
/usr/local/lib/site_ruby/1.8/rubygems/dependency.rb:247:in `to_specs': Could not find rails (>= 0) amongst [] (Gem::LoadError)
from /usr/local/lib/site_ruby/1.8/rubygems/dependency.rb:256:in `to_spec'
from /usr/local/lib/site_ruby/1.8/rubygems.rb:1182:in `gem'
from /var/lib/gems/1.8/bin/rails:18
myhome@myhome-mini:~$ gem env
RubyGems Environment:
- RUBYGEMS VERSION: 1.6.2
- RUBY VERSION: 1.9.2 (2011-02-18 patchlevel 180) [i686-linux]
- INSTALLATION DIRECTORY: /home/myhome/gems
- RUBY EXECUTABLE: /home/myhome/.rvm/rubies/ruby-1.9.2-p180/bin/ruby
- EXECUTABLE DIRECTORY: /home/myhome/gems/bin
- RUBYGEMS PLATFORMS:
- ruby
- x86-linux
- GEM PATHS:
- /home/myhome/gems
- /usr/lib/ruby/gems/1.8
- GEM CONFIGURATION:
- :update_sources => true
- …