Ruby

This article to share is the individual use Ruby to write the crawl page image code, very simple and practical, the need for small partners can refer to. Some time ago to see a lot of people write the next sister script, I also write a ?

A running program often encounters unexpected problems. A file to read does not exist; When you want to save some data, the disk is full; The user may enter inappropriate data. ruby> file = open ("Some_file") ERR: (eval): 1:in ' open ': No such

Now let's analyze the code of some of the previous example programs Bache. The following example appears in a simple Example section. def fact (N) If n = 0 1 Else n * Fact (N-1) End End print fact (argv[0].to_i), "\ n" Because this is the first

The local database creates the order table. Suggestions include the following fields, referring to the official API (HTTPS://PINGXX.COM/DOCUMENT/API): Order_no:required The merchant order number, suitable for each channel requirement for

Ruby annotationNote hides a row for the Ruby interpreter, or part of a line, or several rows. You can use the character (#) at the beginning of the line: # I'm a note, please ignore me. Alternatively, the annotation can follow the same

Use:: To refer to constants (including classes and modules) and constructors (such as Array () or nokogiri::html ()).Never use:: To invoke a method. # bad someclass::some_method some_object::some_method # good

One, string operation string interpolation 1.#{}: Any legitimate Ruby code placed in #{} will be evaluated and replaced with an evaluation result inserted in the original location 2. Single and double quotation marks differ: Double quotes allow

1. Quickly get matching values for regular expressions Usually we use regular expressions, which are match first, and then we take the result, but sometimes we throw an exception, and look at the following example: Copy Code code as follows:

I've been learning about rails, because learning Java is an introductory language. It's a bit of a bad fit. In particular, Ruby's hash. But it's just a matter of thinking it through. It's basically a key-value. There is no big problem with writing

1. Foreword Whether you use Ruby for System management or web development with rails, you may experience recurring tasks that follow a certain period of time (1 hours, 2 days ...). ) to be triggered continuously. In Ruby, I think it's convenient to

Two days ago in the "blog Park" read an article "PHP Basic Course", introduced PHP, feel good. D-Kuala is learning Ruby, just as well as writing a "Ruby starter Tutorial." To illustrate, this article is suitable for programmers who have no access to

Relevance Consulting's Stuart Halloway recently wrote a series of blog posts about the "Ruby vs. Java Geek talk". The inspiration for this series comes from his recent experience with a zero-start, previously constrained Ruby project that has been

Tutorial Requirements The following techniques and resources are required to learn this tutorial: Database server NetBeans IDE 6.0 with Ruby support To create a sample database This tutorial builds the relationship between the Rails model based

In the previous section, we demonstrated how to build a list of items, and this time we built a simple shopping cart based on the previous content. 1. First we want to create a table that holds customer shopping information: Database scripts:

The most frequently run query on a database is to return a conforming result set based on a specified condition, and the query may be to return all the names ' Dave's order, or all the titles on a blog with rails, in many other frameworks and

Today your leader to find you, hope you can help him a little busy, he is now anxious to go to the meeting. What can I do for you? You're curious. He said to you, the current database of your project has a user information table, which contains a

Many times we will find that the real production environment is not a lot of external network, only intranet environment, this time we need to install Ruby, we can not provide the Yum command to install online, this time we need to download the

This example will show you how to escape and un-escape a value to be encoded in a URI and within HTML. Require 'cgi' # Escapename = "Ruby? " Value = "Yes" URL = "Http://example.com /? "+ CGI. Escape (name) + '=' + CGI. Escape (value) +" & Var = t" #

Source and discussion: http://www.blogjava.net/calvin/archive/2005/11/01/17678.html Author: Jiangnan Baiyi The policy-base class in modern c ++ design is the same as that of cpper;The dependency injection of spring-type IOC container is the same

E-books: rubybasics tutorial version 4. This book is a well-recognized introductory tutorial on Ruby in Japan. Song benhong personally reviewed the school and recommended it in sequence. This book supports the new version of Ruby2.0, and also