title: How to dynamically increase the array size?
body: <p>I've been trying to make a program that adds 2 arrays of different size. But I would like to know to to dynamically increase the array size capacity? Ex: array[4] then upgrade the size to 2 to make array[6];?
  EDIT: WIthout using vectors</p>
  
  <p>I tried creating a new ptr but it does not work. I get the error: Read only variable is not assignable.</p>
  
  <pre><code>int *ptr2 = new int[a2.size];
  
  
              // new ptr2 copies ptr1
              for (int i=0; i&lt;(a1.size); i++) {
                  ptr2[i] = a1.ptr[i];
              }
  
  
              // we want ptr1 to point to ptr2
              for (int i=0; i&lt;(a2.size); i++) {
                  ptr2[i] += a2.ptr[i];
              }
  
              delete [] a1.ptr;
  
              a1.ptr=ptr2;
  </code></pre>