title: java operator ++ problem
body: <p>I wonder why first code output is 000 while the second one is 123</p>
  
  <p>first one:</p>
  
  <pre><code>int z=0;
      while(z&lt;4)
      {
         z=z++;
         System.out.print(z);
  
      }
  </code></pre>
  
  <p>second one :</p>
  
  <pre><code>int z=0;
  int x=0;
      while(z&lt;5)
      {
         x=z++;
         System.out.print(x);
  
      }
  </code></pre>
  
  <p>what is the different between these two codes , why the first block do not increase the value of the z ?</p>