Ruby Eval and the Execution of Ruby Code

Ruby EvalRuby is a popular computer programming language, first created in the mid-1990s, in which a programmer writes what are called “objects” that make up the foundation of Ruby’s code. Ruby on Rails is Ruby’s companion web application development technology that helps coders and programmers develop very reliable software. Udemy offers Ruby programming for beginners as well as advanced coding training that provides a thorough understanding of Eval. You can also check out Udemy’s  Ruby on Rails blog for more information on Rails as well as Ruby.

Like many computer languages, Ruby programmers enter or input characters that are then executed or turned into lines of code through a context called a “binding.” Ruby and certain other “object oriented programming languages” all use some kind of “Eval” function utilizing bindings, which take a string of inputted characters and then executes it as code.  The Eval function In Ruby is part of what’s known in Ruby and its hierarchy of coding language as a method.

A Ruby object is manipulated by a programmer who, in turn, makes use of various methods or techniques such as Eval, and through the Object’s “class” then performs whatever function it is the Ruby program’s coder has designed the program to do. Eval is also only one of many methods, classes and objects in Ruby, each having their own use and purpose. Understanding how a language’s eval function works is part of the basics of Ruby programming.

Eval and Running Code

At base, Ruby Eval is simply an expedited way for a programmer to run code in a program written using Ruby. By calling up Ruby’s Eval method a string of inputted characters can quickly be turned into lines of code that are then suitable for running in a Ruby-based program. Here’s an example of a string that’s going to be turned into usable code by Ruby Eval:

#!/usr/bin/env ruby
code = "Time.now"
 result = eval(code)
 puts result

In the example above, the method “Time.now” has been entered into Ruby as a string but it hasn’t yet been executed as code or otherwise looked at or dealt with by Ruby using the program’s interpreter or “translator.” Time.now is simply a string of characters to Ruby and it really means nothing to the program until the programmer calls up the Eval method.

Once Ruby Eval is called, however, the Time.now string will be examined or parsed and then run as if it were actual Ruby code. Running Ruby Eval to execute the string Time.now is really a shortcut for the programmer, but caution should be taken when using any programming language’s Eval function (in Ruby, Eval method) to run code. To utilize Ruby Eval properly it’s necessary to first gain an understanding of its basic purpose and then when it should be used. Udemy.com’s Ruby tutorial for beginners training course is an excellent way to learn about how Ruby eval makes coding fast and easy.

Pros and Cons of Using Ruby Eval

There’s little doubt that Ruby’s Eval method is a quick way to run code in a program created by the language, which is sometimes called “running code on the fly” by code writers and programmers. Ruby Eval also comes with one particularly valuable use, and that’s for the developer console in any Ruby-based program. Using the Eval method in Ruby, a programmer can issue a wide variety of Ruby commands directly to a program instead of trying to write and then run lines of code to address a problem or a bug. Fewer debugging tools are more efficient than Ruby Eval in addressing bugs in a Ruby program.

There are also downsides when it comes to using an Eval function or method in Ruby or any other computer programming language, including whether Eval should ever be used in the first place. Some in the computer science and programming community also consider using Eval to run code in a program to be lazy or in bad form or even to be hacker-like in behavior.

Ruby Eval or the eval function in most any computer language also comes with potential negative security implications in some cases. The Eval method in Ruby as well as in other programming languages is a shortcut. Because it’s a shortcut it may not be wise to use Ruby Eval when data that’s going to be executed and turned into lines of code in a Ruby program comes from an untrusted source on the Internet.

Short-cutting a computer program’s security protection is something that Ruby Eval could do if the programmer using Eval isn’t careful. For example, an attacker trying to hack into a Ruby program could send a string in the data the programmer is pulling from the Internet and then running through Ruby Eval allowing later entry into the program by the attacker. Learning to properly code in Ruby is easy and using Eval makes it even easier. Understanding coding Ruby with security in mind when using Eval is something Udemy.com’s advanced Ruby training course teaches extremely well, so check it out.

Many different computer programs have been written using the Ruby programming language, and the language itself is stable to a very high degree as well as generally secure against hacker-type activities. Ruby on Rails, the programming language’s web development application, has also been used to create many popular Web-based platforms, including Twitter.

Ruby and Ruby on Rails are simple and straightforward and relatively easy to learn. Udemy offers both basic and advanced Ruby and basic and advanced Ruby on Rails training courses that can have any hopeful Ruby and Ruby on Rails programmer up and running and writing code in a very short amount of time. If you’ve finally decided to learn how to write computer code, make the decision as well to let Udemy give you the Ruby and Ruby on Rails training most beneficial to you.