Ruby

1. Ruby's most powerful web framework Ruby on Rails. So you can install Railsinstaller directly.Address: http://www.railsinstaller.org/en. The installation process is checked by default to add an environment to path.2. Change the gem image to http://

What Proc and Lambda have in common: Similar syntaxproc.new{|n| N**2}lambda{|n| N**2} Can be called with the. Call methodHello_proc = proc.new{puts "hello!"}Hello_proc.call #Hello!Hello_lambda = lambda{puts "hello!"}Hello_lambda.call

Chapter I.strings, numbers, classes, and objectsTo prove that Ruby is really good, Hello world can also be written in such a concise way:' Hello World '1. Input/outputPrint ('Enter your name') name=gets () puts ("Hello #{name} ")Note: Ruby is a big

Private methods in rubyThis means that a method can only be called implicitly and cannot be called explicitly. When the receiver is not displayed, self is treated as the receiver. Therefore, only private methods can be called in itself, which is

Http://www.ruby-lang.org/en/downloads/ accessAfter installing Ruby with a third-party tool, you can use macports and rvm to install Ruby on Mac.After actual operations, I think the rvm method is better.Now start to use rvm to install Ruby1. Open the

In Ruby, you checknil?If an object is nil: article = nilarticle.nil? # => true empty?Checks if an element-like a string or an array F. E.-Is empty: # Array[].empty? #=> true# String"".empty? #=> true Rails adds the Methodblank?ToObjectClass:

This is my presentation in the rails lecture of hosei University. I will introduce Sass by 5 examples.   1, what is sass? We can get into the official site of sass. The official site give the definition of sass. Sass is the most mature, stable,

Http://guides.rubyonrails.org/v3.0.8/action_controller_overview.html#the-flash How to display the error message in controller on the page, The Flash is a special part of the session which is cleared with each request. this means that values stored

#! /Usr/bin/ENV rubyclass megagreeter attr_accessor: names # initialize this object def initialize (names = "world ") @ names = names end # Say hi def say_hi if @ names to everyone. nil? Puts "..." elsif @ names. respond_to? ("Each") # @ names is an

Some Problems about Gem, problemsgem Advanced Software Engineering When I was doing advanced software engineering jobs today, I encountered some problems: After the new git clone a ruby rails projectBundle InstallSystem Error   Prompt"Gem install

Ruby optimized inheritance class instances and ruby inheritance instances In the Rails principles, there are statements about simplifying the Controller and enriching the Model. The following example shows a simple inheritance optimization.

No such file to load -- readline solution after Ruby upgrade, rubyreadline After ruby and rails are upgraded, script/consystemic appears:Copy codeThe Code is as follows:/Usr/local/lib/ruby/1.8/irb/completion. rb: 10: in 'require ': no such file to

A deep understanding of the caching mechanism in Ruby on Rails, rubyrails Scenarios First, let me show you several pages in ChangingThePresent.org. I will display several locations on the site that need to be cached. Then, we will point out the

Tutorial on implementing simple thing-Driven web applications using Ruby, rubyweb Introduction For Web applications, automated integration testing is a very important part. However, because these test cases are too dependent on the implementation

Use Ruby to write a tutorial on accessing the Twitter command line application, Introduction Twitter has become a leader in social networks. Twitter only allows users to publish content of no more than 140 characters. Who can think of it? This

Tutorial on using the mechanism in Ruby: rubymechanic In Ruby, web page capturing is usually implemented using the mechanism, which is very simple to use. InstallCopy codeThe Code is as follows:Sudo gem install mechanicCapture webpagesCopy codeThe

Tips for creating strings IN Ruby: ruby Summary % {String} is used to create a String enclosed by double quotation marks.% Q {String} is used to create a String enclosed by double quotation marks. Copy codeThe Code is as follows:Str = A stringEND_OF_

Conditional judgment exists in programming languages. The conditional judgment in Ruby is similar to that in Java. Of course, there are still some differences. Conditions for condition determination in Ruby: 1) Comparison operations such as =, can

Recently, there is a need to display the number as a fixed number of digits. If the number of digits is insufficient, add it as zero. For example, five digits:Copy codeThe Code is as follows:3-> 00003292-> 0029212422-> 12422Ruby is easy to

N + 1 Problems N + 1 is the most common performance problem in database access. First, let's introduce what N + 1 is: For example, there are two tables in our database: MERs and Orders. Orders contains a foreign key mermer_id pointing to the