title: C++ how to check cin input is A-Z pattern
body: <p>C++ how to check <code>cin</code> input is <code>A-Z</code> pattern</p>
  
  <p>How do i check if the following</p>
  
  <p><code>cin &gt;&gt; input;</code></p>
  
  <p>and input is <code>A-Z</code> , means not number , and is <code>A</code> to <code>Z</code>;</p>