http://stackoverflow.com/questions/998979/difference-between-and-in-rails/25617607#25617607 http://stackoverflow.com/questions/7996695/what-is-the-difference-between-and-in-erb-in-rails <% %> Executes the ruby code within the brackets. <%= %>…

只是怕忘了命令,全部撸一次,记个大概.. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 安装Ruby之前,先要安装RVM: curl -L https://get.rvm.io | bash –s 然后,安装一些依赖之后: rvm install ruby version --with-openssl-dir=$HOME/.rvm/usr 之后安装Rails: gem install rails --version 4.0.0 --no-ri --no-rdoc 创建Rails新程序…

Ruby学习笔记4: 动态web app的建立 We will first build the Categories page. This page contains topics like Art, Home & Living, and Kids, so our users can browse through categories and find what they like. Each Category in our site will need to store information…

rvm是一个命令行工具,可以提供一个便捷的多版本ruby环境的管理和切换. https://rvm.io/ 如果你打算学习ruby/rails, rvm是必不可少的工具之一. 这里所有的命令都是再用户权限下操作的,任何命令最好都不要用sudo. rvm安装 $ curl -L get.rvm.io | bash -s stable $ source ~/.bashrc $ source ~/.bash_profile 修改 RVM 的 Ruby 安装源到国内的 淘宝镜像服务器,这样能提高安装速度…

梅尔刻度 梅尔刻度(Mel scale)是一种由听众判断不同频率 音高(pitch)彼此相等的感知刻度,表示人耳对等距音高(pitch)变化的感知.mel 刻度和正常频率(Hz)之间的参考点是将1 kHz,且高于人耳听阈值40分贝以上的基音,定为1000 mel.在大约500 Hz以上,听者判断越来越大的音程(interval)产生相等的pitch增量,人耳每感觉到等量的音高变化,所需要的频率变化随频率增加而愈来愈大. 将频率$f$ (Hz)转换为梅尔$m$的公式是: $$m=2595\log_…

--reference Java Heap Memory vs Stack Memory Difference 在数据结构中,堆和栈可以说是两种最基础的数据结构,而Java中的栈内存空间和堆内存空间有什么异同,以及和数据结构中的堆栈有何关系? 一.Java 堆存储空间 堆内存(堆存储空间)会在Java运行时分配给对象(Object)或者JRE的类.只要我们创建了一个对象,那么在堆中肯定会分配一块存储空间给这个对象.而我们熟知的Java垃圾回收就是在堆存储空间上进行的,用以释放那些没有任何引用指向…

I believe the biggest distinction is that a stub you have already written with predetermined behavior. So you would have a class that implements the dependency (abstract class or interface most likely) you are faking for testing purposes and the meth…

在国外看到详细的说明一篇,非常浅显透彻.转给国内的筒子们:-) 原文标题: Spring中的<context:annotation-config>与<context:component-scan>到底有什么不同? 原文出处:http://stackoverflow.com/a/7456501 <context:annotation-config> is used to activate annotations in beans already registered in…

ref:http://stackoverflow.com/questions/271743/whats-the-difference-between-b-and-strong-i-and-em They have the same effect on normal web browser rendering engines, but there is afundamental difference between them. As the author writes in a discussio…

Difference between SendRedirect and forward is one of classical interview questions asked during java web developer interview. This is not just applicable for servlet but also for JSP in which we can use forward action or call sendRedirect() method f…