title: Undefined function sha256()
body: <p>I have this php code:</p>
  
  <pre><code>$password = sha256($_POST['password']);
  </code></pre>
  
  <p>but when I run this code it says:</p>
  
  <pre><code>Fatal error: Call to undefined function sha256() in .... on line ...ix it as 
  </code></pre>
  
  <p>What is wrong with this code and what must I do to fix this as I know that <code>sha256</code> exists.</p>
  
  <p>I have also tried:</p>
  
  <pre><code>$password = sha256(trim($_POST['password']));
  </code></pre>
  
  <p>But that doesn't work either.</p>