title: Calling an object from a class with Default Constructor
body: <p>I'm wondering what a call to an object is supposed to display. I have a class called big_number that has a few different constructors. In another method, I'm declaring an object 'a' using class big_number as follows:</p>
  
  <pre><code>big_number a;
  
  cout &lt;&lt; "Default constructor gives " &lt;&lt; a &lt;&lt; endl;
  </code></pre>
  
  <p>And my constructor is:</p>
  
  <pre><code>big_number::big_number()
  {
      head_ptr = 0;
      tail_ptr = 0;
      positive = false;
      digits = 0;
      base = 10;
  }
  </code></pre>
  
  <p>(Although I'm sure that this constructor is wrong).</p>
  
  <p>The full code of the testing file:</p>
  
  <pre><code>    int main()
  {
      int n1, n2;
      unsigned int base;
      string s;
  
      char choice;
      do
      {
          cout &lt;&lt; "Type 'd' to test default constructor" &lt;&lt; endl;
          cout &lt;&lt; "Type 'i' to test int constructor" &lt;&lt; endl;
          cout &lt;&lt; "Type 's' to test string constructor" &lt;&lt; endl;
          cout &lt;&lt; "Type 'a' to test assignment" &lt;&lt; endl;
          cout &lt;&lt; "Type '&gt;' to test input operator" &lt;&lt; endl;
          cout &lt;&lt; "Type '=' to test comparison operators" &lt;&lt; endl;
          cout &lt;&lt; "Type 'q' to quit" &lt;&lt; endl;
          cin &gt;&gt; choice;
  
          if (toupper(choice) == 'D')
          {
              big_number a;
              cout &lt;&lt; "Default constructor gives " &lt;&lt; a &lt;&lt; endl;
          }
  //More Code
  </code></pre>