Ruby language application. What is "Ruby"? Ruby programming language. Important personal qualities

Ruby programmers- These are specialists who have extensive experience, technical knowledge, and use a dynamic programming language. Developers use this language to create websites, web interfaces, corporate applications, and software. The profession is suitable for those who are interested in computer science (see choosing a profession based on interest in school subjects).

Short description

The Ruby language, which is open source, was created in the early 90s by a Japanese developer and became publicly available in 1995. Ruby did not immediately leave Japan, because in the first years of its existence not a single document was translated into European languages. Only in the late 90s did technology appear. the documentation is in English, and many developers have become interested in the programming language in question.

Note that there is still very little technical literature translated into Russian, so the developer must know English or Japanese. Today this programming language is among the Top 5 most popular, giving way to the leading positions of Java, JavaScript and PHP.

Ruby will be difficult for a person without specialized education to master. Only those programmers who have been using C#, C++ or Java for several years will be able to work with it. Ruby has a simple syntax, multi-threaded programming, support for exception handling, and data is objects.

Features of the profession

The work of Ruby programmers is no different from the work of developers using JavaScript or PHP. Their tasks include creating software, its debugging and further maintenance. The programmer's responsibilities are determined by the company in which he works:

• improving and finalizing the functionality of online stores, applications, etc.;
• technical support for plugins in various systems;
• creation of Android applications, web applications, games, platforms and other products;
• database architecture design;
• testing and debugging of created software;
• interaction with designers, developers and other team members;
• project management.

Pros and cons of the profession

pros

1. A simple and understandable dynamic programming language.
2. A small number of experienced Ruby developers, which increases the value of the profession in the eyes of the employer.
3. If you have professional knowledge, you can master Ruby quite quickly.
4. Stable and high salary, receiving bonuses subject to successful work.
5. You can work in the office or remotely, planning your own working day.
6. Constant career growth.
7. Developers achieve success very quickly, because you can become a Ruby Senior at the age of 25-30 years.
8. You can start working while still studying, which will bring both profit and experience.
9. A large number of online courses and free programmers ready to teach students.

Minuses

The need to remember a lot of information.

The work is often routine.

The developer communicates little with people, especially if he works remotely.

A specialist spends a lot of time at the computer, so at a young age he may experience blurred vision, back pain and other occupational diseases.

Important personal qualities

1. Peace of mind, because you often have to do work in emergency mode.
2. Complete dedication and patience, which especially concerns the lack of a work schedule, making endless changes, and correcting mistakes.
3. Communication skills, because it is necessary to find a common language with designers, customers, and third-party programmers.
4. Modesty and intelligence.
5. Honesty and technical competence.
6. Creative journey.
7. Integrity.
8. No bad habits.
9. Resourcefulness.

Ruby programmer training

Universities

Place of work

1. IT companies.
2. Advertising agencies.
3. Private software developers.
4. Banking system.
5. Other organizations that need a programmer to operate.

Career

A Ruby developer, like any other programmer, can expect stable professional growth, but its speed depends on the person’s knowledge, skills and personal ambitions. In the first 3 months of work, the programmer is an apprentice, after which each year of experience will bring him a new status:

• Junior (up to 18 months of experience);
• Middle (up to 3-4 years of experience);
• Senior (more than 4 years of experience).

The classification may be different, but the principle remains the same: more experience means better position and higher salary.

Ruby Programmer Salary

Salary as of 02/03/2020

Russia 30000—120000 ₽

Moscow 50000—230000 ₽

Professional skills

1. Knowledge of Ruby and Ruby on Rails.
2. Experience with PHP, Java, C++, etc.
3. At least 2-3 years of experience in programming is required.
4. Knowledge of foreign languages ​​is required.
5. Knowledge of MySQL, PostgreSQL, JSP, HTML, UnitTest, Grails, CSS.
6. Git, Subversion or Mercurial.
7. Development of technical documentation.

Useful materials

1. Russian-language forum about Ruby: onrails.club.
2. Website with translations for Ruby: rusrails.ru.
3. Chris Pine Learn to Code.
4. Michael Fitzgerald "Learning Ruby."
5. Giovanni Sakti, Nia Mutiara, Hafis Bari Lubis "Learning Devise for Rails".

Today there are a lot of programming languages ​​that have their own characteristics and patterns. This article will discuss one of them.

History of the Ruby language

Ruby has been around as a programming language for quite some time. Work on the edition of this currently known language began for the first time in 1993. The first official version was released in 1995. The creator of the language is Yukihiro Matsumoto. His enthusiasm for programming was noticed while still a student, but the idea of ​​creating his own tool appeared much later. So, what is special about this programming language? What made you so popular on the world stage?

The Ruby programming language is quite interpreted. This is a high-level language with dynamic typing and execution-environment-independent implementation of multithreading. It has its own garbage collector. In terms of syntax features, it is closest to the Perl languages. As a result of the widespread development of the ecosystem, this platform took a lot from Smalltalk, Python, Lisp and other programming languages. Of great importance is the fact that the Ruby language and its implementation are completely free. It follows from this that everyone has the opportunity to propose their own changes. If they are accepted by the community, they will be included in the next version of the language.

Ruby Philosophy

In the process of creating his own brainchild, Matsumoto, being a devoted fan and enthusiast of object-oriented programming, became the author of a certain philosophy for programmers who choose to learn his language. Thus, the Ruby programming language is designed to create simple and straightforward applications. The main emphasis was on the simplicity and readability of the code, and not on the speed of the program. This is precisely the reason that this platform is often chosen as the input platform necessary for training programmers. The basic idea on which this language is based is the principle of “least surprise.” What does this mean?

And the fact that the program should behave as the programmer expects from it. An important part of the language ideology introduced by the creator is its great variability. Thus, it is possible to achieve the same result in different ways and functions. This allows each programmer to solve the problem as he sees fit from the point of view of correctness and convenience. This is what, in most cases, has influenced the popularity of the language among information technology professionals.

Main characteristics

What does Ruby mean when considering it as a programming language? First of all, it is an object-oriented language. There are no primitive types because all structures and data units are considered objects. This distinguishes it from the same Java language, where there are primitive data structures. All functions in Ruby are a method. Most of the properties and capabilities were introduced by the authors from other programming languages. Thus, we can safely say that Ruby contains the best qualities of many other languages ​​and technologies. For example, the Ruby ecosystem has its own garbage collector.

His idea was taken from Smalltalk and Java. It is capable of working with all objects in the system. This mechanism makes it possible to clear memory from objects that are no longer needed, which happens unnoticed by the application user and developer. The garbage collector helps the developer not to be distracted by managing the application's memory. This way he can focus his full attention on functionality and usability.

Paradigms of language

Some programmers who answered the question of what Ruby represents as a multi-paradigm language found themselves in the heat of the debate. This language makes it possible to apply any of the programming paradigms with equal success. Of these, it is worth highlighting the following:

Procedural programming style;
object-oriented approach;
functional approach.

The developer is allowed to choose the paradigm that is closest to him. It should be borne in mind that this will make his set of tools more limited or weaker. The Ruby programming language only adheres to this choice.

Reasons for fame

In most cases, this language has become famous due to the ease of developing various additions to it. Thus, the number of frameworks and libraries is constantly increasing, and the tasks they solve independently enable developers to bring the product to a finished state in the shortest possible time. Ruby programming is often associated with the creation of web applications, as well as supporting the functioning of various sites and Internet platforms. The language was able to occupy this niche due to its own simplicity and speed of development. It is worth noting that alternative platforms (for example, Java) require a significantly larger amount of knowledge and experience designed to solve similar problems.

Famous frameworks

Speaking about well-known frameworks existing on the market today, it is worth noting Rails among them. Most users who answer the question of what Ruby is, intuitively mean RubyOnRails. This set of software elements is an industry standard among developers. It is regularly supported, is in constant development, and is replenished by the programming community. It is worth noting that despite all this, it remains free.

The presented framework is capable of describing the components of a web application within the boundaries of the MVC (Model-View-Controller) pattern. In addition, it is ready to provide ready-made integration with the application server, as well as an interface that allows access to the database. These three components make it possible to literally write and launch a simple blog or private web page on the Internet in a matter of hours. It is possible to create even native mobile applications in the Ruby programming language. This is achieved by using the RubyMotion library. It can run Ruby code on iOS, OS X, and Android platforms. This library was developed by a private group of vendors. This means that you will have to pay for use, but it is another confirmation of the wide capabilities of the language.

The Importance of Writing Tests

Another important component of the Ruby language ecosystem, as well as its web-oriented part, consists of frameworks and libraries designed for writing tests. RubyOnRails uses the BDD (behavior-driven development) philosophy. This means that the programmer first develops a sequence of tests that describe the expected behavior of the program. It then creates the code needed to pass those tests. RSpec is considered the unspoken standard in this area. It is a framework that makes it possible to write test cases in a language that even inexperienced users can understand.

Ruby Gems

Due to the detailed standard that Ruby packages and libraries must comply with, creating add-ons is easy. Thus, among gems it is possible to find modules designed to solve almost any problem, from integration with social networks and third-party resources to ready-made platforms for e-commerce. To use a third-party library, it is enough to describe the dependence of your own project on a specific library that is located in a remote or local repository. During subsequent assembly, this library is loaded into the application automatically. This solution greatly simplifies project migration between creators, because there is no need to share dependencies to build the project manually.

Thus, we can conclude that Ruby is a powerful and versatile programming language that is suitable not only for experienced developers, but also for beginners.

There are many programming languages ​​designed to perform different tasks. Each of them is characterized by a unique set of operators and special syntax.

In today's article we will look at the three most popular languages ​​used in web development: PHP, Ruby and Python. We will find out what they look like, how they differ from each other, how popular they are and among what audience.

As a result, you will understand which language is more suitable for solving your problems, and which one is worth learning:

PHP: the most popular language for the Internet

PHP (Hypertext PreProcessor, hypertext preprocessor) is a programming language executed on the web server side, designed Rasmus Lerdorf(Rasmus Lerdorf) as a tool for creating dynamic and interactive websites.

This language turned out to be quite flexible and powerful, so it has gained great popularity and is used in projects of any scale: from a simple blog to the largest web applications on the Internet:

Advantages of PHP:

• is free software distributed under a special license (PHP license);
• easy to learn at all stages;
• supported by a large community of users and developers;
• has advanced database support;
• there are a huge number of libraries and language extensions;
• can be used in an isolated environment;
• offers native tools for organizing web sessions, a program interface for extensions;
• is a fairly complete replacement for Microsoft's proprietary ASP (Active Server Pages) environment;
• can be deployed on almost any server;
• ported to a large number of hardware platforms and operating systems.

Disadvantages of PHP:

Popularity:

According to Wikipedia, as of January 1, 2013, PHP was installed on more than 240 million websites (39% of all surveyed) or 2.1 million web servers.

Usage

Scripts written in PHP are usually stored in files with the .php extension, which contain a mixture of regular HTML tags with special markup: an opening tag:

Ruby: an interpreted, pure OOP language

Ruby is a dynamic imperative object-oriented programming language developed by Yukihiro Matsumoto. Ruby was influenced by languages ​​such as Perl, Eiffel and Smalltalk.

It is characterized by dynamic typing and automatic memory management. The Ruby language is used in web development as part of the open web framework Rails, more commonly called Ruby on Rails (RoR):

Benefits of Ruby:

• open development;
• works on many platforms;
• can be embedded in HTML markup;
• refers to ultra-high-level programming languages ​​(VHLL), that is, it has a high level of abstraction and a subject-specific approach to the implementation of algorithms;
• implements a conceptually pure object-oriented paradigm;
• provides advanced string and text manipulation techniques;
• easily integrates high-performance database servers (DB2, MySQL, Oracle and Sybase) into its programs;
• thanks to VHLL, Ruby programs scale well and are easy to maintain;
• simple and clean syntax makes it much easier for programmers to take their first steps in learning this language;
• there is a simple software interface for creating multi-threaded applications;
• has advanced tools for working with arrays;
• The language's capabilities can be expanded using libraries written in C or Ruby;
• reserved words can be identifiers if this does not create ambiguity for the parser;
• additional security features;
• built-in debugger.

Disadvantages of Ruby:

• learning a language beyond beginner level can be challenging;
• there are clearly not enough information resources dedicated to Ruby;
• Ruby is less productive than many other languages ​​used in web development;
• Ruby is relatively slow to develop and evolve.

Projects using Ruby:

• Google SketchUp;
• 37signals;
• GitHub;
• Shopify;
• Indiegogo;
• Basecamp.

Popularity

According to official Ruby website, this language is one of the ten most popular programming languages. The growth in popularity of the language itself is due to the popularity of software products written in Ruby, especially RoR.

Usage

Program files written in Ruby have the extension .rb. These files can be run as shell scripts using an interpreter. For example, given that the Ruby interpreter is in /usr/bin :

Python: a general purpose programming language

Python is widely used as an interpreted language for scripts for various purposes (although there are also Python language translators).

Like Ruby, Python aims to bring the syntax of a real program written in it closer to the pseudocode describing the task, which allows the programmer to reduce the size of the program. The idea of ​​creating this language arose in the late 1980s and was implemented Guido van Rossum.

The language's elegant design and efficient, disciplined syntax make it easy for programmers to collaborate on code. Python is a multi-paradigm programming language: it allows you to combine a procedural approach to writing code with an object-oriented and functional one:

Python benefits:

• open development;
• quite easy to learn, especially at the initial stage;
• syntax features encourage the programmer to write highly readable code;
• provides tools for rapid prototyping and dynamic semantics;
• has a large community that is positive towards newcomers;
• many useful libraries and language extensions can be easily used in your projects thanks to an extremely unified import mechanism and program interfaces;
• modularity mechanisms are well thought out and can be easily used;
• absolutely everything in Python is an object in the OOP sense, but the object approach is not imposed on the programmer.

Python Disadvantages:

• not very good support for multithreading;
• Not many high-quality software projects have been created in Python compared to other general-purpose programming languages, such as Java;
• lack of commercial support for development tools (although this situation is changing over time);
• initial limited means for working with databases;
• Benchmarks show Python's performance to be poorer than that of mainstream Java VMs, giving the language a reputation for being slow.

Projects using Python:

• Yahoo Maps;
• Zope Corporation;
• Linux Weekly News;
• Shopzilla ;
• Ultraseek.

Popularity

According to Wikipedia, Python is firmly among the 8 most popular programming languages ​​according to version TIOBE Programming Community Index. And if we do not count separately languages ​​with C-like syntax (C++, C#, ObjectiveC, Java, etc.), then Python is the third most popular language.

Usage

The python interpreter can be used both to run scripts and in interactive shell mode.

Type in the command line:

$ python to get the interpreter prompt: Python 2.4.3 (#1, Nov 11 2010, 13:34:43) on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> Now you can type a line in Python and press Enter to execute it: >>> print "Put some text here" Put some text here

Need for specialists

Based on a Jobs Tractor analysis of more than 45,000 developer jobs posted on Twitter over the past year, the need for programmers is as follows:

• PHP – 8238 people required;
• Ruby – 2937 people;
• Python – 1587 people.

Of course, statistics are not the only factor to consider when learning a programming language.

What programming language is worth learning?

Most programmers will tell you that you can do anything in any of the programming languages ​​described in this article. In fact, there is no better or worse option here. All languages ​​are good. But when choosing a language, you should focus on the goals you want to achieve.

If you are just starting to learn web programming, then after mastering the basics of the language, you will sooner or later be faced with the need to learn some kind of framework based on it. Web frameworks make it much easier to create applications.

Most sites have an obvious set of basic functions: session handling and authorization, request validation, etc. The framework frees you from having to rewrite all these functions again when creating the site. As a web programmer, you will only have to design and implement the functions of how the site interacts with the user.

Developed frameworks that include functions for working with user data (articles, topics, posts, photos, etc.) are called content management frameworks (Content Management Framework - CMF).

If you add to this the interface elements for the end user of the site, you get a so-called content management system or CMS (Content Management System). CMS allows you to get a website with a prototype interface and minimal functionality immediately after installation or after certain settings, that is, without programming at all.

At the same time, most CMS provide the programmer with both a CMF programming interface and an interface for expanding its functionality.

This is the first of a series of articles in which I'll talk about the features of Ruby and Ruby on Rails and share tips on where to start learning Ruby, where to find answers to questions, how to get the experience you need, and how you can set yourself apart from other candidates. I would be glad if my advice helps someone decide on their specialization and choose Ruby to study and work with.

Key Features and Differences of Ruby

I often hear the question: is it worth learning Ruby? As a rule, the question is based on doubts: how easy it is to find a job with this specialization, whether there will be interesting projects, and so on and so forth. Ruby is a modern, constantly evolving programming language; there are many areas of application for it. Surely you have heard about Chef, Vagrant, Homebrew, but most often we all hear about Rails. Here is a post with a commentary from the author of the framework about why it is worth learning Rails.

Of course, everyone decides for themselves which tool to use. And there is no point in arguing endlessly about why one technology is better than another. I chose Ruby because it is an incredibly expressive and flexible language that allows you to solve the same problem in many ways.

Ruby is an interpreted, fully object-oriented programming language with strong dynamic typing. It combines Perl-like syntax with an object-oriented approach. Also, some features are borrowed from the programming languages ​​Python, Lisp, Dylan and CLU. The cross-platform implementation of the Ruby language interpreter is distributed under open source software. Code written in Ruby can be understood even by a person who does not understand programming. Projects such as Redmine, Twitter, Shopify, Basecamp, GitHub, Kickstarter, Airbnb and others were created on RoR.

With the rise of Node.js, the popularity of Ruby on Rails has waned somewhat, but tech startups often use RoR due to its ease of prototyping. Ruby is the 11th most popular language in the TIOBE index.

Benefits of Ruby

• Large and friendly community.
• The barrier to entry is quite high, which means that a Ruby developer is likely to have experience with at least one other programming language.
• You use only those libraries and modules that are needed.
• There are a large number of useful libraries that are ready to use (Ruby Gems).
• There is a lot of information on Ruby on the Internet, in a structured and sifted form.
• In the context of discussing Ruby, one cannot fail to mention the most popular framework Ruby on Rails.

Now let's talk about some of the benefits of Ruby in more detail.

Development speed

One of the advantages of Ruby and the RoR framework is the speed of development. Personal experience and the experience of colleagues shows that solving problems in Rails is one and a half times faster compared to other similar frameworks. Ruby is very simple as a tool, and there are a huge number of ready-made solutions for various kinds of problems.

Standard data caching tools

When developing a large-scale project, one of the most important aspects is caching. Ruby on Rails comes standard with standard data caching tools. That is, you will immediately have tools for caching data on the project, and you can easily cache individual blocks of code or even entire pages.

Tests first, code later

Often during the development of large projects the question of testing arises, and it is not uncommon when there is no additional funds for a separate team of testers. Rails has a solution to this problem as well. If you compare RoR with other frameworks in the context of application testing, you will find a lot of ready-made solutions for any type of tests, be it integration or unit. All these libraries work out of the box. Ideally, in a Ruby on Rails project, no code is written until tests have been written for it. RoR ideology involves the initial use of BDD (Behavior Driven Development) or TDD (Test Driven Development) methods.

Commonly accepted development process standards for Ruby developers

When talking about the benefits of Ruby, I can't help but mention the Ruby community again. It is constantly growing, developing and is always ready to help. There is always someone who will tell you how best to solve a problem and share their experience in any matter.

Also a very important point - in the Ruby community for many years there have been standards for the development process, certain rules/community agreements according to which development is carried out, which greatly simplifies the work. Due to these standards, each project is highly structured; accordingly, a new developer in the team will quickly get up to speed and be useful from the first days of work. And even more: if the project was started by one team and finished by another, this is also not a problem at all. Since the development is carried out according to the already mentioned rules and community agreements, the new team will quickly and easily understand the project and successfully complete it without much loss of time.

Ruby on rails also has a large number of different ready-made solutions in the public domain. Most solutions have already been implemented by someone before you and also tested by the community, which reduces the need to develop from scratch. These could be authentication, authorization, commenting systems, payment systems, mailing lists, and so on.

Ready-made solutions for project multilingualism

Rails comes with very powerful tools for project localization out of the box. It is possible to both provide support for several languages ​​initially, and implement it later. The project contains special files for translating terms, tools for displaying templates in different languages, and much more.

High level of data protection

Nowadays, articles about hacking of various resources are often published online. The developers of the Ruby on Rails framework took the issue of data protection very seriously. RoR initially includes encryption of passwords, credit card data and other personal user data; SQL injections and XSS attacks are also excluded. All input parameters are escaped by default.

Learning Ruby

Now let's talk about how exactly you can master Ruby.

Theory

We should start, of course, with literature. I recommend these sources:

• Ruby in 20 minutes is a good resource for complete beginners. Allows you to familiarize yourself with the basic structures of the language in less than half an hour and start writing your own small programs.
• Codecademy is a platform with online courses in a variety of areas, including pure Ruby and Rails. The educational process here is structured quite interestingly, theoretical material is given and immediately a practical task to consolidate it. The final tasks are paid, but even without them you can gain the necessary skills.
• Materials on Ruby and Rails - a collection of links to various sites and books dedicated to the study of Ruby and Rails.
• I can especially recommend the book Flanagan D., Matsumoto Y. “The Ruby Programming Language”. It is considered one of the best, its author is the creator of the Ruby language.
• Google :)

Here are a couple of resources to get you started:

• w3schools.com/sql - here you can read, try and test your knowledge of SQL.
• quizful.net/test - here you can find questions that are often asked during interviews.

English

I believe that there is no point in dwelling on this point in detail, since this is the topic of a separate article. English is very important and this is a well known fact. I would just like to briefly mention the two most important points.

Firstly, English is the main language of the international community, accordingly, most of the useful literature will also be in English, many news, reports and important articles will also appear first in English. If you want to know the answer to any question, there is a very high probability that first of all you will be able to find it in English.

Secondly, the better your English skills, the greater your chances of finding a job. Most clients are foreign, therefore, knowledge of English is important for productive communication, a clear understanding of the technical specifications and good contact with the client.

Practice

After studying several resources, it is worth moving on to the more important part, namely practice. There are a lot of examples of tasks with an online store or a simple blog on the Internet (here is one of them), especially when it comes to Rails. In the course of completing tasks that are already a little closer to real ones, you will definitely encounter some problems and then you will move on to training one of the most important qualities - the ability to Google. Unfortunately, I couldn't find any tutorials or courses dedicated to this skill, but it definitely plays a very important role in everyday work.

Courses

After reading the theory and writing several “pet projects”, you can, of course, try to go for interviews, but it often happens that this knowledge is not enough. This is due to the large influx of candidates, and given the competition, everyone is trying to stand out and prepare as best as possible.

Another important point in training that can be an advantage in your favor when looking for a job is programming courses. Unless, of course, you have a mentor who is willing to spend a certain amount of time coming up with assignments and reviewing them.

I’ll say right away that I under no circumstances recommend taking courses without already having some knowledge. I see courses as a great way to consolidate the knowledge gained through self-study. And now I’m not trying to advertise any particular school, but I’ll explain exactly what benefits can be derived from this:

With a high degree of probability there you will learn something you didn't know before. The courses have a fairly large volume of material, which is presented in a structured form, which allows you to better assimilate the material.

During the course you will have mentor, who will review the solution to your problems and point out weaknesses and errors.

Motivation. This is primarily for those who need help with self-discipline. Sometimes it’s quite difficult to force yourself to do something, no matter what prospects loom on the horizon. When attending courses, you will have a clear schedule to follow and assignments to complete or you will be expelled. Financial motivation also plays a role here in the case of paid courses. After all, when you give your hard-earned money, you have a completely different attitude towards the matter, and thoughts of simply taking a walk arise much less often.

Another advantage - certificate. It is clear that in the end you will be assessed on your knowledge, and not on the presence of pieces of paper in your resume. But nevertheless, this will be a plus, especially if there is a candidate with a similar level of knowledge, but without documentary evidence.

Plus one project on GitHub to your piggy bank. If you are a novice developer, then most likely the project written in the courses will be more interesting from a technology point of view than those that were written previously.

And the most important thing - employment. When talking about courses, I don’t mean only those for which you need to pay money. Often companies themselves recruit for training so that they can hire the best ones later. This could be an in-house course or an internship/internship. This option is the best, since you don’t have to pay for anything, you get experience and all the above advantages and, in addition, a real job prospect. It is more difficult to get into them, but the prospects are more significant.

Total

Ruby is a language that allows you to work without a lot of the hassle and fuss that comes with strongly typed languages. Ruby is easy to get started with, especially if you already have experience developing in other programming languages, and you'll be able to quickly prototype with Ruby on Rails. In Japan, where it originated, Ruby was used to create games. Ruby is concise and reads like English, making the code easy to understand for beginners.

When it comes to learning Ruby, I want to reiterate: you need to start small. Read a few books, do a few assignments on your own, and then, if you feel the need to gain more knowledge and experience or additional motivation, you can take courses already having a certain amount of knowledge acquired on your own.

Ideally, these are courses from a company that will make you an offer upon completion if you perform well. An alternative option is paid courses that will help you consolidate your knowledge, add another project to your resume, and gain experience, which is most important at the start. But you shouldn’t expect that after completing paid courses you will easily pass an interview by showing your certificate. In any case, knowledge will be assessed.

At the same time, if you have enough motivation, patience, abilities and experience with other programming languages, you can easily master Ruby on your own, since there is a lot of useful and well-structured information on the Internet. Also, thanks to the open and large Ruby community, you can easily find online answers to many possible questions that, with a high degree of probability, someone has already asked before you.

Have fun learning! And in the next article we will talk about code.

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Ruby is one of the youngest programming languages. Its creator, Yukihiro Matsumoto (also known as Matz), a professional Japanese programmer, says:<<Я начал разработку Ruby 24 февраля 1993 года. Первая hello world программа на Ruby заработала летом того же года, а aльфа-версия была готова к декабрю 1994.>> The name of the language comes from the name of the gemstone ruby ​​(by analogy with another widely used programming language Perl: pearl).

Here's how its author characterizes Ruby:<<Это мощный и динамический объектно-ориентированный язык с открытыми исходниками. Ruby работает на многих платформах, включая Linux и другие реализации Unix, MS-DOS, Windows 9x/2000/NT, BeOS и MacOS. Главная цель Ruby — эффективность разработки программ, и пользователи найдут, что программирование на нем эффективно и даже забавно>> .

In Japan, Ruby has become popular since the first publicly available version in 1995, but the availability of documentation only in Japanese has limited its further adoption. Only in 1997 did a description of Ruby appear in English, and in 1998 the ruby-talk forum opened. From that moment on, Ruby began its march around the world. Over the past year, three English-language books dedicated to him have appeared (see), although, unfortunately, none of them have yet been translated into Russian. Ruby is now included in most Linux distributions and is also available to users of other operating systems.

Please note that this article is not a language reference guide. A brief introduction can be found in the electronic textbook, and more complete information can be found in and, as well as on the Internet sites already mentioned above. The main purpose of the article is to give people who are already familiar with various programming languages ​​a general idea of ​​the features of Ruby, to show its power and beauty, to explain that it is equally good as a first programming language and as a tool for the work of a professional programmer and system administrator.

Programmers talk about Ruby

In this section we will present statements about the Ruby language collected from various sources, postponing for a while consideration of examples that illustrate them. Most of the issues that will be raised assume that the reader has some knowledge in the field of language theory and object-oriented programming. Ruby is easiest to understand for those who know Smalltalk, Lisp, C, C++, and Perl.<<Джентльменский>> a set of Perl, Java and C++ is also a very good starting position for learning Ruby.

Those who cannot boast of such knowledge will be very pleased to know that

* <<если для изучения языка Perl Вам нужно потратить, скажем, три недели, то Python Вы изучите за неделю, а Ruby — за один день!>>

* <>.

In the introduction, we already quoted Yukihiro Matsumoto, the creator of Ruby. Here's what else he says about this language. So Ruby

* has a simple syntax;

* supports exception handling;

* allows you to redefine operators;

* is a purely object-oriented language (complete, full, pure object oriented language), in which, unlike Java or Perl, everything is an object;

* allows you to work with integers of arbitrary size;

* does not require declaration of variables;

* uses prefixes (@, $, @@) to set the scope of variables;

* supports multi-threaded programming.

One of the first papers to draw attention to Ruby was a now somewhat outdated article by Hal Fulton.<<Тридцать семь причин, по которым мне нравится Ruby>>. Here are some of them.

Ruby is a dynamic language. Unlike static languages ​​like C++ or Java, methods and variables in Ruby can be added or overridden at runtime. This allows, for example, to avoid the #ifdef conditional compilation directives required by the C language. This is where Ruby's similarities to languages ​​such as Lisp and Smalltalk come into play.

Ruby is an interpreted language. Since this property has a negative impact on performance, I would like to give some comments. Firstly (and most importantly), a fast development cycle is the most important advantage that<<перевешивает>> some shortcomings. Secondly, although Ruby is not catastrophically slow, in cases where speed is absolutely necessary, you can write part of the code in C. Finally, thirdly, no one said that someday a Ruby compiler would not be written .

Ruby has the ability to work with regular expressions. At one time they were used only in some utilities of UNIX systems (grep, sed, vi). Then, thanks to the Perl language, a significant number of people recognized its power in word processing. Ruby makes it possible to harness this power with even greater ease.

Remember Isaac Newton's famous phrase<<Если я видел дальше, чем другие, то только потому, что стоял на плечах гигантов>>? Ruby is definitely<<стоит на плечах гигантов>>, including Smalltalk, CLU, Lisp, C, C++, Perl, Kornshell and other languages. Ruby contains all the best that humanity has accumulated in the field of programming languages. At the same time, the following three principles are observed: do not reinvent the wheel, do not fix what is not broken, use the knowledge and experience available to programmers. In Ruby, knowledge about files and streams from the UNIX OS, and the specifications of the printf function from the standard input/output library of the C language, and the ability to work with regular expressions in Perl will be useful.

Ruby is a scripting language. This should not be considered to characterize the language as<<игрушечный>> or not powerful enough. Such a language must be interpreted and capable of replacing batch files that interact with the operating system and control the behavior of other programs.

Ruby is a versatile and flexible language. With its help, you can equally elegantly implement both what is traditionally done using the Kornshell interpreter and what is usually written in C.

In terms of simplicity and richness of possibilities for working with strings and arrays, the Ruby language has no competitors. Arrays are dynamic and can be manipulated like sets, stacks, and queues. There are also associative arrays, working with which is also extremely simple and convenient.

A large number of libraries have already been written for the Ruby language. Threads, sockets, objects saved between program runs, CGI programs, databases, GUIs - all of this can be used when programming in Ruby.

Dave Thomas and Andy Hunt, co-authors of the first Ruby book published in English, spoke to Dr. Dobb's Journal" (January 2001) say:<<Возьмите чисто объектно-ориентированный язык Smalltalk и избавьтесь от его причудливого синтаксиса. Добавьте комфорт и мощь языка Perl, но без всяких специальных случаев и магических преобразований. Заверните получившееся в ясный синтаксис, основанный частично на языке Eiffel, и добавьте понемногу от Scheme, CLU, Sather и Common Lisp. У вас получится Ruby.>> In fact, this means that Ruby is a natural and almost inevitable result of the evolution of modern programming languages. The authors of this article agree with this point of view.

I would like to emphasize that Ruby is not a panacea for solving all programmers' problems. One should not abandon the use of Java and C++ languages ​​where their use is justified. On the other hand, it is not wise to underestimate the practical application of Ruby in real projects.

Let's now listen to the statements of the best representatives of the programming community who compare Ruby with other languages.

Let's start with the Java language:

* Ruby is an interpreted language;
* in Ruby everything is an object (in Java there are int and Integer types, which creates certain inconveniences);
* variables in Ruby are not statically typed and do not require declaration;
* modules in Ruby allow you to use<<миксинов>> (mixins) construct similarities to interfaces (interfaces) of the Java language, while allowing the implementation of methods in them.

Now let's compare it to Perl:

* Ruby is much easier to learn, easier to program, and written programs are easier to maintain;
* in Ruby, prefixes (@, $, @@) describe the scope, not the type of the variable;
* Ruby borrows regular expressions, the $_ variable, and much more from Perl.

Let's complete the comparison of Ruby with other languages ​​by considering one of the closest<<конкурентов>> - Python language. This comparison is especially interesting because Python is now considered by many as a good candidate for the role of the first programming language. So let's compare Ruby to Python:

* control constructs and methods in the Ruby language end with the end keyword, while Python uses the so-called<<двумерный>> syntax when a sign of completion is a change in the number of leading spaces in the next line of the program;
* instead of self in Ruby, the @ prefix is ​​used to denote instance variables;
* in Ruby, unlike Python, the concepts of type and class are synonymous;
* Python does not support inheritance and does not allow you to add methods to existing types;
* the garbage collection algorithm used in Ruby makes it easier to write implementations of methods in C;
* extensions for Ruby written in C/C++ allow you to define new classes;
*Ruby is often faster than Python.

And again we will give the floor to the creator of the language. His statement about plans for further work on Ruby, expressed in the form of one of the control constructs of the language, will allow us to smoothly move on to considering examples of real programs.

loop do read and reply mails write code write document/article/book write code end

Programmers write in Ruby

Let's start with examples that show that knowledge of the input/output libraries of the C and C++ languages ​​is also useful in Ruby.

printf "Number: %5.2f; Line: %s", 1.23, "Hello!" endl = "n"; $stdout<< 17 << " красных шариков" << endl line = gets; print line

The special global variable $_ always contains the result of the last read operation. It is also used as the default argument in many constructs. The following program, for example, prints all lines from the input stream that contain the word Ruby.

while gets # assigning the next string to a variable $_ if /Ruby/ # matching it with the Ruby pattern print # printing $_ end end

ARGF.each ( |line| print line if line =~ /Ruby/ )

An ARGF in Ruby is an object that represents the concatenation of the contents of all files whose names are given on the command line, or simply the standard input stream (in the case of no arguments).

Here's what a Ruby program looks like to calculate the factorial of a number given as a command line argument:

def fact(n) return 1 if n == 0 f = 1 while n>0 f *= n n -= 1 end return f end print fact(ARGV.to_i), "n"

To calculate using this program located in the fact.rb file, the value is 100! just run the command ruby ​​fact.rb 100.

The three programs below that recursively calculate the 30th Fibonacci number compare the performance of Ruby, Python, and Perl.

# Ruby def fib(n) if n<2 n else fib(n-2)+fib(n-1) end end print fib(30), "n" # Python def fib(n): if n<2: return n else: return fib(n-2)+fib(n-1) print fib(30) # Perl sub fib { my($n)=@_; if ($n<2) { return $n; } else { return fib($n-2)+fib($n-1); } } print fib(30), "n";

Another classic problem is to determine, using the Sieve of Eratosthenes, a list of all prime numbers not exceeding a given number (100 by default).

max = Integer(ARGV.shift || 100) sieve = for i in 2 .. max sieve[i] = i end for i in 2 .. Math.sqrt(max) next unless sieve[i] (i*i) .step(max, i) do |j| sieve[j] = nil end end puts sieve.compact.join ","

As the next example, consider a solution in Ruby to a problem that is often asked of first-year C/C++ students: given a text file, determine the number of occurrences of each word in it. Using associative arrays and a number of standard file and string techniques allows you to write an extremely concise and clear program.

freq = Hash.new(0) while gets() for word in $_.split(/W+/) freq += 1 end end for word in freq.keys.sort! print word, " -- ", freq, "n" end

Here are two simple examples of using the standard class library. As a result of executing the first program, it will be found that 7/8+1/8=1, and 7/8*1/8=7/64; the second one will calculate (1 + i)64.

require "rational" a = Rational(7,8) b = Rational(1,8) print a, "+", b, "=", a+b, "; ", a, "*", b, " =", a*b, "n" require "complex" a = Complex(1,1); print a**64

Without further explanation, here are two equivalent programs that illustrate the operator override for the SongList class. An associative array (hash or dictionary) allows indexing by arbitrary objects, not just integers. In this case, the operator allows you to find the desired song not only by number, but also by its name.

class SongList def (key) if key.kind_of?(Integer) return @songs else for i in [email protected] return @songs[i] if key == @songs[i].name end end return nil end end class SongList def (key) return @songs if key.kind_of?(Integer) return @songs.find ( |aSong| aSong .name == key ) end end

Because Ruby inherits the best features of many languages, there are usually several different options available to perform fairly standard tasks. Here are 13 (!) different ways to type the numbers 0 to 9:

i = 0 i = 0 while i< 10 begin print i , " " print i , " " i += 1 i += 1 end end while i < 10 i = 0 i = 0 until i >= 10 begin print i, " " print i, " " i += 1 i += 1 end end until i >= 10 for i in for i in (0..9) print i, " " print i, " " end end for i in (0...10) 10.times do |i| print i, " " print i, " " end end 0.upto(9) do |i| 9.downto(0) do |i| print i, " " print i, " " end end (0..9).each do |i| (0...10).each do |i| print i, " " print i, " " end end i = 0 loop do if i< 10 then print i, " " else break end i += 1 end

Finally, a question for those who don't know Ruby: what will the following program print?

print ["L", "R", "H", "T"].collect ( |x| x.succ )

If you can guess the answer, then this will be the best confirmation of the fact that Ruby is an intuitive language. If you don't guess, then you will have another reason to study it.

Ruby and beginners

This language is undoubtedly one of the best as a first programming language. The fast development cycle (edit-run-edit), use of an interpreter, native object-orientation, untyped variables that do not require declaration - all this allows students to concentrate their attention on the general principles of programming.

No less important is Ruby's multiplatform nature and its membership in the world of free software. Another weighty argument in its favor is the possibility of practical use of the language in a wide variety of areas, which will not allow a professional who grows out of a beginner to regret wasted time.

It can be noted that a significant number of the requirements listed above are satisfied by Python, Java, C++, and even (to a lesser extent) Delphi. The last of them, however, is a commercial product, which should automatically entail its exclusion from consideration. However, in Russia, even among the organizers of programming competitions for schoolchildren, there are people who claim that the cost of the Delphi distribution is about 70 rubles!

Let's first try to compare the Ruby and Java languages, looking at them through the eyes of a person just starting to get acquainted with the world of programming. For such a person, the clarity and brevity of programs, the absence of strange and incomprehensible things in them, are extremely important.<<магических>> words. Namely, the Java version of the traditional first program consists mainly of them!

public class Hello ( public static void main(String args) ( System.out.println("Hello, world!"); ) )

A similar program in Ruby won’t take long to explain:

puts "Hello, world!"

Ruby is a very friendly language in this sense. A program written by a beginner can be very short and contain nothing superfluous, but creating such a program requires, basically, only common sense.

Unlike the Java language, there is no problem in Ruby<<больших>> numbers. The above programs for calculating the factorial of a number or Fibonacci numbers, when written in Ruby, always give the correct result. In the case of the Java language, restrictions on the range of representable integers lead to absurd (from the point of view of a school student or first-year student) equalities like

An unpleasant surprise for a person just starting to learn programming!

Another important factor is the simplicity of the methods Ruby uses to enter data from the keyboard or from a file. In the case of the Java language, the complexity of these operations must be carefully masked, protecting the beginner from unnecessary problems.

The compactness of the Ruby distribution and the ease of its installation on any operating system allow a schoolchild or student to work on a home computer without any problems. Again the comparison is not in favor of Java!

Python is similar to Ruby in many ways. Of the above differences between these two languages, for the situation of initial programming training we are considering, it turns out to be especially significant<<двумерный>> syntax used in the Python language. This feature is not initially clear and gets in the way at first. In general, the main argument in favor of Ruby as a first programming language is its intuitive clarity and predictability, and not its many other advantages.

Ruby and professionals

What is Ruby good for a professional programmer and system administrator? Much has already been said above, but here are some more interesting examples and brief comments.