Changing Rails Versions

This article introduces how to change Rails versions in the Ruby programming language.

When doing rails new, you may need to specify a version. For example, in the rails tutorial, you need notation like rails 4.2.2 new sample_app. At this time, if rails 4.2.2 is not installed, an error will occur.

To install rails with a specified version, use the following:

gem install rails -v 4.2.2

Check how many versions are installed

gem search ^rails$ -l

Then, this happens

PS Y:\files\pg\railsenv\sample_app> rails -v
Expected string default value for '--rc'; got false (boolean)
Rails 4.2.2
PS Y:\files\pg\railsenv\sample_app> cd ..
PS Y:\files\pg\railsenv> rails -v
Rails 5.1.1