title: What does the regular expression /_/g mean?
body: <p>JavaScript:</p>
  
  <pre><code>.replace(/_/g," ");
  </code></pre>
  
  <p>I have it in my code but can't remember why or what it does! Can one of you regular expression gurus help?</p>
  
  <p>I know this may seem basic, but regular expressions are not my cup of tea and googling for <code>/g</code> didn't help much.</p>