title: JavaScript regex with parentheses does not work
body: <p>I am trying to write the regex which would detect the string of the form <code>(123)4567890</code>. The string in which we have a parenthesis in the beginning, three arbitrary digits, parenthesis after and seven arbitrary digits after.</p>
  
  <p>Here is my regex:  </p>
  
  <pre><code>const plainTenDigitsTwoParentheses = /^( \(\d{3}\)\d{7} )$/.test("(123)4567890");
  </code></pre>
  
  <p>The regex above produces <code>false</code>, while I would expect it to produce <code>true</code>. What am I missing here?</p>