title: Difference between 0 and 0u
body: <p>Text from a textbook:</p>
  
  <blockquote>
    <p>The uint type is 32-bit unsigned integer type. Its default value is
    the number 0u or 0U (the two are equivalent). The 'u' letter indicates
    that the number is of type uint (otherwise it is understood as int).</p>
  </blockquote>
  
  <p>Then is there a difference between 0 and 0u? If not, then why is the default value '0u'. What is the advantage of suffixing an integer with 'u'?</p>
  
  <p>Why would I ever have to use, say '5u', instead of just using '5'? </p>