title: Byte arithmetic: How to subtract to a byte variable?
body: <p>I'm getting an error when I'm trying to do somethink like this:</p>
  
  <pre><code>byte a = 23;
  a = a - 1;
  </code></pre>
  
  <p>The compiler gives this error:
  Test.java:8: possible loss of precision found   : int required: byte
               a = a - 1;
                     ^ 
  1 error</p>
  
  <p>Casting doesn't solve the error...
  Why the compiler don't let me do it? 
  Should I need to transform the variable 'a' into an int?</p>