title: Bitwise "& " on a long?
body: <p>I want to obtain the least 32 bits from a number of type long, so I perform bitwise operation "&amp;" on the number with bits mask 0xFFFFFFFF, but the result is not correct, it still contains the other bits.</p>
  
  <p>for example:</p>
  
  <pre><code>long a = 0x1234567890ab; 
  long b = (a &amp; 0xffffffff);
  </code></pre>
  
  <p>I expect the value of b to be 0x567890ab</p>
  
  <p>but in practice, it is still 0x1234567890ab</p>