title: Looking for a regular expression to validate 10 digit numbers on separate line
body: <p>I want to validate user entered values which </p>
  
  <pre><code>a. Starts with 2
  b. 10 digit in length
  c. could be multiple numbers separated by new line
  </code></pre>
  
  <p>example.</p>
  
  <pre><code>2123123123 - Valid
  
  2123123123
  2987654321 - Valid
  
  2123123123
  newline    - Invalid
  </code></pre>
  
  <p>I am using expression as <code>"^[2]\d{9}(?:\r\n[2]\d{9})*$"</code>. it works only if I enter one 10 digit number but not working for multiple numbers on newline</p>