title: Declaring an array in C without giving size
body: <p>When declaring an array like this:</p>
  
  <pre><code>int array[][] = {
      {1,2,3},
      {4,5,6}};
  </code></pre>
  
  <p>I get an error saying: "Array type has incomplete element type"</p>
  
  <p>What is going on??</p>