title: Solidity accessing private variable
body: <p>currently, I'm practicing solidity. However, I'm a little confused about accessing a private variable in a contract.</p>
  
  <p>For example here;</p>
  
  <pre><code>address private a;
  address private b;
  mapping (bytes32 =&gt; uint) public people;
  mapping (bytes32 =&gt; mapping(address =&gt; uint)) public listOfEmp;
  bytes32[] public list;
  bytes32 private z;
  </code></pre>
  
  <p>I can access 'a' with</p>
  
  <pre><code>web3.eth.getStorageAt("0x501...", 0)
  </code></pre>
  
  <p>How can I access 'z' here? From a different contract.</p>
  
  <p>Thank you</p>