title: Bit wise operator
body: <p>Take any number of following type 2, 2^2(=4), 2^3(=8) , 16 ,32 , 64 ...</p>
  
  <p>If we will make ORing (|) of two numbers like </p>
  
  <pre><code>2| 4 = xyz 
  0010 | 0100 = 0110 
  </code></pre>
  
  <p>then for checking this whether this number xyz contains any of the given numbers we make ANDing of xyz with that number and if we get that number again we can say it contains that number </p>
  
  <pre><code>0110 &amp; 0010 = 0010 
  </code></pre>
  
  <p>can we use this property for optimizing our code ? 
  or in any other practical solution ? </p>