Ruby

Configure the Ruby environment before installing cocoapods, this article summarizes how to install the ruby environment. Installing the ruby environment requires first installing Xcode and then installing homebrew, and then installing RVM to install

1. Creating an array A=array.new (6,obj=nil) #=> [nil, nil, nil, nil, nil, nil] set default valuesA=array.new (6) #=> [Nil, nil, nil, nil, nil, nil] The default value is nilA=array.new (6,obj=1) {|obj| obj+1} #=> [1, 2, 3, 4, 5, 6] default values

Modify viewsModify the index view (app/views/posts/index.html.erb) and add the edit link as follows:our blogs That is, add the following logic: Among them, Edit_post_path, is the previous "[Ruby on Rails] and I learned route map" referred to

How to quickly and correctly install Ruby, Rails running environmentHttps://ruby-china.org/wiki/install_ruby_guideFor newly-introduced developers, how to install Ruby, the operating environment of Ruby Gems and Rails can be a problem, this page

In Ruby rails, if you want to save a property (or read a property), and you want to do something else when you save the property (or read a property)You can use the method that overrides the property's setup or reader.For example, a models table has

Demand:Students copy questions and do problemsInitial code#-*-encoding:utf-8-*-#Student A's Test paper classclassTestpaperadefQuestion1 puts'Yang had to get, later gave the Guo Jing, refining into the sword, the Dragon Sword of the Xuan Iron may be [

Some important differences between Ruby and C # are as follows: 1. Ruby is a dynamic language, and C # Is a static language-that is, after an object is new, Ruby can dynamically add some attributes or methods to the object instance (as does

  [Root @ localhost Ruby] # gem install passenger -- preError: Error installing PASSENGER:Passenger requires fastthread (> = 1.0.1, runtime) Solution: Download   Copy the file to the current directory and execute: Gem install fastthread-1.0

The full name of yarv is yet another Ruby Vm, which is another Ruby Virtual Machine implemented by Sasada Koichi. At present, Ruby's virtual machine is completed through AST (Abstract syntax tree), which is slow and can only be used for pure script

Page 3Overview Description and execution: Python and Ruby are highly interactive;○ Compilation and execution: Pascal, C, fast.N local execution, such as C, C ++;N virtual machine execution, such as Java, C #. ○ Dynamic languages,

I. Numbers Ruby supports integers and floating-point numbers. integers can be of any length. Integers within a certain range are stored in binary. They belong to the fixnum type. If they exceed this range, they are automatically converted to

1. Common Ruby data types: Numbers, strings, booleans my_num = 25my_boollean = true (or false)my_string = "Ruby" 2. Common mathematical operators in ruby Add (+) minus (-) multiplication (*) Division (/) power (**) Evaluate remainder (%) 3. Ruby

Recently, there is a need to use a string as a class. For example: There is a string "chinamag" that calls methods under the chinamag Class Based on this string.   Solution: 1. rails can use the constantize method. Pry (main)> 'chinamag'.

You may think the following chart is interesting, because it is a quality data filtering algorithm written in three programming languages (Ruby, Java, C/C ++: sieve of Eratosthenes) Well, obviously Ruby is slow, and it is about 1.5 orders of

From http://biodegradablegeek.com/2008/04/how-to-post-form-data-using-ruby/ PostIng data on web forms is essential for writing tools and services that interact with resources already available on the web. you can grab information from your Gmail

Differences between the access control operators public, private, and protected in Ruby, and rubyprivate Focus on private and protectedPublic The default value is public, which can be accessed globally.Private C ++, "private" indicates "private to

Scaffolding is a very easy method for rails. Some simple addition, deletion, modification, and query scaffolding can be implemented, saving unnecessary trouble. How can we use rails scaffolding? Let's explain it today. . Specify the port to start

% Q Used to replace double quotation marks. When you need to put a lot of quotation marks in the string, you can directly use the following method without adding a backslash (\ ") One by one before the quotation marks (\")Copy codeThe Code is as

I. Numbers Ruby supports integers and floating-point numbers. integers can be of any length. Integers within a certain range are stored in binary. They belong to the fixnum type. If they exceed this range, they are automatically converted to the

You can use Ruby to view the function source code in the command line. To view the source code of the update_attribute function of ActiveRecord, a common method is to search for def update_attribute directly in the Rails source code. The Pragmatic