title: How to have ruby 2.3.1 as a default version
body: <p>I am an absolute beginner of ruby on rails and even web development.</p>
  
  <p>I use Mac OS(El captain 10.11.3)</p>
  
  <p>I would like to ask you how I can use ruby 2.3.1 anytime I would like to develop my project. It seems like that I can use ruby 2.3.1 for good. (Below is the version I would like to use)</p>
  
  <pre><code>ruby -v
  ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-darwin15]
  </code></pre>
  
  <p>This may sound odd, but whenever I get my terminal closed, the version of ruby in my laptop goes back to </p>
  
  <pre><code>ruby -v
  ruby 2.0.0p645 (2015-04-13 revision 50299) [universal.x86_64-darwin15]
  </code></pre>
  
  <p>So when I try to develop my project, I always do this</p>
  
  <pre><code>source ~/.bash_profile
  </code></pre>
  
  <p>The above command allows me to use ruby 2.3.1.</p>
  
  <p>What I want to do is not to put the command "source ~/.bash_profile" when I open my ruby project.</p>
  
  <p>Has anyone encountered any similar problem before? If you have, please leave your comments below. English is not my first language, so if this post does not make sense or you need more information, please let me know as well</p>
  
  <p>Any advice would be appreciated! Thanks in advance!</p>