title: make string of N characters
body: <p>Say I have a <code>number=20</code> and a <code>$value=7</code>.</p>
  
  <p>If I want to make a string of 20 7's using PHP. what's the quickest way to make this?</p>
  
  <p>So output like:</p>
  
  <pre><code>$a='77777777777777777777';
  </code></pre>
  
  <p>Any functions to make this easier?</p>