title: Id returned 1 exit status
body: <p>This error pops when I try to compile this (sorry its in spanish)</p>
  <pre><code>#include &lt;iostream&gt;
  #include &lt;string&gt;
  
  using namespace std;
  
  //////////////////////////////
  // Contacto
  
  class contacto
  {
      private:
          string nombre;
          string apellido;
          string numTelf;
          string numCel;
          string correo;
          string ciudad;
          string pais;
          string grupo;
      public:
          contacto (string nom, string apel, string tel, string cel, string cor, string ciu, string pai, string grup)
          {
          nombre = nom;
          apellido = apel;
          numTelf = tel;
          numCel = cel;
          correo = cor;
          ciudad = ciu;
          pais = pai;
          grupo = grup;       
          }
          void getContacto (string nom, string apel)
          {
              
          }
  };
  
  class agenda
  {
      private:
          contacto arreglo[40];
      public:
      agenda();
          void setContacto(int n)
          {
          }
  };
  
  
  
  int main ()
  {
  int op, N;
  agenda agen;
  
      cout&lt;&lt;&quot;N:&quot;;
      cin&gt;&gt;N;
      agen.setContacto(N);        
      
      
  system(&quot;pause&quot;);
  return 0;
  }
  </code></pre>
  <p>I know it has something to do with the object declaration and the constructor of the agenda class, ive tried to erase it but ill just give me other errors, I just need to access the agend.setContacto(N); but it keeps giving me errors, and as the Agenda class only has an array of objects, I dont know how to make a valid constructor.</p>
  <p>Ill leave the classes out here to make it easier to see:</p>
  <p>class contacto:</p>
  <pre><code>class contacto
  {
      private:
          string nombre;
          string apellido;
          string numTelf;
          string numCel;
          string correo;
          string ciudad;
          string pais;
          string grupo;
      public:
          contacto (string nom, string apel, string tel, string cel, string cor, string ciu, string pai, string grup)
          {
              nombre = nom;
              apellido = apel;
              numTelf = tel;
              numCel = cel;
              correo = cor;
              ciudad = ciu;
              pais = pai;
              grupo = grup;
          }
          void setContacto (string nom, string apel, string tel, string cel, string cor, string ciu, string pai, string grup)
          {
              nombre = nom;
              apellido = apel;
              numTelf = tel;
              numCel = cel;
              correo = cor;
              ciudad = ciu;
              pais = pai;
              grupo = grup;           
          }
          void getContacto (string nom, string apel)
          {
              
          }
  };
  </code></pre>
  <p>class agenda:</p>
  <pre><code>class agenda
  {
      private:
          contacto arreglo[40];
      public:
      agenda();
          void setContacto(int n)
          {
  };
  </code></pre>
  <p>EDIT: The error that pops is</p>
  <blockquote>
  <p>[Linker error] undefined reference to `agenda::agenda()'</p>
  <p>ld returned 1 exit status</p>
  </blockquote>
  <p>EDIT2: The contacto class just needed an empty constructor for the Agenda class to initialize the array</p>