Version 2.0: Added keyword arguments Added %i() syntax for symbol arrays. Version 1.9: Changed block variables to require local variables Introduced syntax for hashes with symbol keys Many incompatible changes. To provide an idea of what might change, here's a short list of some major changes to Ruby over the past few major versions at the time of this writing: Eventually, you're going to write or use a Ruby program that needs a different version of Ruby, and that's when you will find that you need a Ruby version manager. However, this won't always be the case: Ruby is an evolving language with features added, modified, and deleted with every new version. If you do rely on such features, the ones you use all run well in whatever version of Ruby you use, so you're not even aware that you're using version-specific features. Chances are, the programs you've written so far are "version agnostic" that is, they don't rely on features of Ruby that depend on any specific ruby version. If you're just getting started with Ruby, you may wonder why you could possibly need to use more than one version of Ruby. Ruby version managers are programs that let you install, manage, and use multiple versions of Ruby. In this chapter, we will talk about those topics. Specifically, we did not discuss what ruby version managers are nor what services they provide to a developer who is writing and using Ruby programs. In that discussion, we casually mentioned that ruby version managers play a role in how Ruby uses Gems. (These examples are from a MacOS machine).In the previous chapter, we discussed RubyGems and how they interact with Ruby and your local file system. ruby-version is read automatically, and you’re automatically switched to the correct version of Ruby before you start working.įor example, you might have this sequence: % cd ~/projects/older-project It is very convenient because it hooks into the cd ( change directory) command. RVM is typically installed ( link) on a Linux, Unix or MacOS machine. Popular tools to help you manage your Ruby version are: ruby-version file, which simply specifies a version number, for example: 2.4.2 Many Ruby (or Rails) projects will include a simple. There are a couple of tools which are popular for this, but both have agreed to share a common file. This makes it much easier to manage multiple projects on your development machine, each expecting a different version of Ruby.
#Rvm manage multiple ruby versions code
If you don’t specify which version of Ruby your project needs, it can be very confusing when code works on one machine, but not another.Īs with most languages, it’s considered good practice to specify the version of Ruby that your code expects. This means that your project now also relies on Ruby 1.9 features. How does this cause problems?įor example, you might have decided to use a Gem which internally relies on Ruby 1.9 features. This older code will run on any version, but the newer syntax will only run on Ruby 1.9+.
Probably the most visible change came with Ruby 1.9. This means that it is important to be clear about which Ruby version your code expects. And like many languages, there have been syntax changes across versions.
Ruby has been in constant development since the 1990s.
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