title: "printf" on strings prints gibberish
body: <p>I'm trying to print a string the following way:</p>
  
  <pre><code>int main(){
      string s("bla");
      printf("%s \n", s);
           .......
  }
  </code></pre>
  
  <p>but all I get is this random gibberish.</p>
  
  <p>Can you please explain why?</p>