[Ruby on Rails Learning 1] ubuntu14.04 configure rvm and ruby, ubuntu14.04rvm
To install ruby, you must first install rvm.
Rvm is Ruby Version Manager, a command line tool developed by Wayne E. Seguin. Rvm allows you to easily install and manage ruby productivity environmen
Introduction to Ruby operators and statement priority, ruby operator priority
Ruby is a language with strong expressive power. It is proud of its rich operators and syntactic sugar. Although Ruby has always regarded the principle of least surprise as one of its philosophies, but it is often surprising that it is diffic
Object array sorting in Ruby and Ruby object array sorting
Sorting of Ruby object arrays
The author has just come into contact with Ruby, because he previously thought that the script language syntax is not standardized and he is somewhat biased against the script language. For example, he does not need to learn PYTHON
Array usage in Ruby, ruby array usage
Ruby arrays are ordered. What about any object ?? The set of integer indexes. The elements in each array are associated and an index is mentioned.
Array subscript starts from 0, such as C or Java. Negative index assumes that the end of the array --- that is,-1 indicates the array index of the last element,-2 is the next eleme
Some basic operations on Ruby processing time, And ruby processing basic operations
Get the current date and time:
The following is a simple example to get the current date and time:
#!/usr/bin/ruby -wtime1 = Time.newputs "Current Time : " + time1.inspect# Time.now is a synonym:time2 = Time.nowputs "Current Time : " + time2.inspect
This produces the following res
is not a professional web crawler crawling, just before a very bad site to help people brush the ticket started to learn the web crawler tools.The initial time is to use the Python urllib2, get the page when the text processing, later in the forum to see the Beautifulsoap this level of artifact, Python processing this is really convenient, but later I met the Ruby and rails, from the faithless, Even read the metaprogramming
Some basic knowledge about modules in Ruby and basic knowledge about Ruby modules
A module is similar to a class. It can also be called a class that cannot be instantiated ". Because the Class is a subclass of the Module Class, it may be better to say "Class = Module + instantiation Capability.
What is the so-called module used? There are two main types of functions: Mix-in and namespace.
Mix-in is actually
Explain the concept of range in Ruby and the concept of Ruby range.
The scope is everywhere: From January 1, January to January 1, December, from December 9 to December 9, 50 to 67 rows, and so on. Ruby supports a range and allows us to use multiple methods:
As sequence range
As condition range
Range
As sequence range:
First, it may be the most natural us
Four Methods for Equality judgment in Ruby and four methods for ruby equality judgment
It has long been known that ruby has four equality judgment methods: "=", "=", and "equal ?" And "eql ?", It is used in common programs, but I feel that I lack a deep understanding of it. When I read some of the rails source code today, I cannot determine the meaning of one of
We strongly recommend that you use the following Online Learning Websites: http://tryruby.org:
Ruby returns the last value in the method by default.
To return multiple values, you can use an array.
You can return a value by forcibly declaring return.
The basic output method is to use puts (output line) and print (print directly ).
The Basic Input Method is gets (read a row that contains '\ n' at the end of the row, which can be eliminated by cho
Basic Learning notes for Ruby metaprogramming and ruby learning notes
Note 1:The Code contains variables, classes, and methods, collectively referred to as language construct ).
# test.rbclass Greeting def initialize(text) @text = text end def welcome @text endendmy_obj = Greeting.new("hello")puts my_obj.classputs my_obj.class.instance_methods(false) #false means not inheritedputs my_obj.instance_variable
Assignment related operations in Ruby programming and ruby programming assignment
In earlier versions of Ruby, the return value of the value assignment statement is the return value of the method that sets this attribute. In Ruby1.8, the value of the value assignment statement is always the value of the parameter, and the return value of the method is lost.
class
Share with us today the basic Ruby Tutorial (http://www.maiziedu.com/course/ruby-px/), which focuses on Ruby Source and Ruby features, here's a look at Ruby 's introduction:Ruby is a purely object-oriented programming language. It was created in 1993 year by as of Japan (まつ
Example of writing code for exception handling in Ruby, and ruby Exception Handling
A single exception uses the fail keyword only when an exception is caught and thrown repeatedly (because you do not fail here, but are accurate and intentionally throw an exception ).
begin fail 'Oops' rescue => error raise if error.message != 'Oops' end
Do not specify an accurate RuntimeError for fail/raise.
# bad
Tutorial on interrupt and return in Ruby programming and tutorial on ruby programming usage
The use of the return, break, and next keywords involves the issue of jumping out of the scope. Their difference lies in the different scopes of different keywords jumping out, because there are code blocks, you need to pay special attention to them.ReturnCommon Methods
Generally, the return statement is the same as
Example parsing for Hook methods in Ruby and ruby hook instance Parsing
By using the Hook method, we can intervene in the life cycle of Ruby classes or modules, greatly improving programming flexibility.The following hook methods related to lifecycle are available:
Classes and modules
Class # inherited
Module # include
Module # prepended
Module # extend_
Let's get back to our jukebox for a moment (remember the jukebox ?). At some point
We'll be working on the code that handles the user interface-the buttons that people
Press to select songs and control the jukebox. We'll need to associate actions
Those buttons: press START and the music starts. It turns out that Ruby's blocks are
A convenient way to do this. Let's start by assuming that the people who made
Hardware implemented a Ruby extension that gi
1. Debug comment Print output debugRuby is an interpreted language, a script, and on Linux, scripts cannot be executed in three ways:1. Run the script with the interpreterInterpreter script FileThat is:Ruby script File2. Run the script directlyIn the script file, use the#! Script InterpreterDefine the script interpreter path, then grant the script execute permission, then run directly./script FileCan.3. Run the script inside the interpreter[Email protected]:/home/ywt/ror_tests/ruby_tests# irb
The example explains the Hook method in Ruby and adds a hook to the method call. The example explains ruby.
The Hook method is similar to the event-driven device. You can execute a specific callback function after a specific event occurs. This callback function is the hook method (more vividly described: The Hook method can be like a hook, hook up a specific event .), In Rails, The before \ after function i
Detailed description of the code block and parameter transfer in Ruby, detailed description of ruby code transfer
1. Block DeclarationAfter the function is called, the block declaration is enclosed by {...}, Or do. end encapsulation. {} Is generally used in single-line statements, and do... end is used in multi-line statements.
(1 .. 4). each {| v | print "# {v}"} # output 1 2 3 4
Blocks can contain paramet
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