http://persumi.com/u/fredwu/tech/e/blog/t/constantize Persumi - Level up your writing and blogging with AI Blog Tech Fri, 01 May 2026 23:27:30 +0000 Fri, 26 Feb 2010 06:33:00 +0000 http://persumi.com/u/fredwu/tech/e/blog/p/rails-tip-string-constantize http://persumi.com/u/fredwu/tech/e/blog/p/rails-tip-string-constantize Blog Tech ifredwu@gmail.com (Fred Wu) <![CDATA[<p> So we want to dynamically instantiate an object (i.e. convert a string to a class constant).</p> <p> Instead of doing this:</p> <pre><code class="ruby language-ruby">@dynamic_var = "User" eval(@dynamic_var)</code></pre> <p> You can do this:</p> <pre><code class="ruby language-ruby">@dynamic_var = "User" @dynamic_var.constantize</code></pre> <p> See more about the <code class="inline">constantize</code> method in <a href="http://apidock.com/rails/ActiveSupport/CoreExtensions/String/Inflections/constantize">Rails’s API</a>.</p> ]]> http://persumi.com/u/fredwu/tech/e/blog/p/rails-tip-string-constantize