Upgrade Ruby to the latest version under Mac

Upgrade Ruby to the latest version under Mac
I found that the version of ruby is too low when installing other software. Now I am preparing to upgrade Xia ruby.
View ruby version
Command: ruby --version
Prompt version is as follows, it should be upgraded:
ruby 2.0.0p481 (2014-05-08 revision 45883) [universal.x86_64-darwin14]
Upgrade ruby
     Inquiry online using brew method
     Command: brew install ruby
     At this point, you will be prompted as follows, upgrade Homebrew first, and then a long waiting process, you can drink saliva and wait for a while.
     After the installation is complete, execute the command to check the version and find that it is still 2.0.0. The version has not changed. You should also set environment variables through Baidu.
Setting environment variables
       Open the file: vi .bashrc
       Enter the following: export PATH = / usr / local / Cellar / ruby / 2.5.1 / bin: $ PATH
       Execute the import command: source .bashrc
Check the version again
     ruby --version
    The message is as follows, and you're done:
    ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-darwin14]
Upgrade Ruby to the latest version on Mac