title: Find size of array pointed to by pointer
body: <p>I have the below code:     </p>
  
  <pre><code>int* d = (int*) malloc(100 * sizeof(int));
  cout&lt;&lt;"size of d which is pointer is: " &lt;&lt; sizeof(d)&lt;&lt;endl;
  </code></pre>
  
  <p>I know that sizeof outputs 4 as d is a ptr. But, how can I find the sizeof the entire array using sizeof</p>