title: Why won't IRB work after I mistyped a string?
body: <p>I started to learn Ruby using IRB and wrote the wrong code below:</p>
  
  <pre><code>irb(main):001:0&gt;"amefurashi".delete(aiueo")
  </code></pre>
  
  <p>I noticed it was missing a double-quote mark, and the prompt changed to:</p>
  
  <pre><code>irb(main):002:1"
  </code></pre>
  
  <p>I wrote the correct code:</p>
  
  <pre><code>irb(main):001:1"amefurashi".delete("aiueo")
  </code></pre>
  
  <p>but why won't it work?</p>