title: Assert user input is capital letter
body: <p>I have to write a program where the user is supposed to enter a string.  The first and the second character have to be capital letters, and the rest have to be numbers.  If the user does not enter this correctly, the program is supposed to generate a messate informing about the imput error.</p>
  
  <p>I know I could do this by writing a loop which scans every single sign in the user input and looks for mistakes.  </p>
  
  <p>So say I have defined:</p>
  
  <p>char sign;</p>
  
  <p>And I use a loop with charAt(loop number)</p>
  
  <p>Can I do the scanning of capital letters in an easier way than writing, say:</p>
  
  <pre><code>if (sign != 'A' || sign != 'B' || sign !='C' || sign != 'D' . . . .)  
  </code></pre>
  
  <p>for all letters?  This is kind of a tedious way to write the program.  So if anyone know any shortcuts/methods for asserting the input is a capital letter, I would greatly appreciate it!</p>