title: which way for constructor is best?
body: <p>There are two ways construct a class:</p>
  
  <pre><code>  class Cell{
    public:
          Cell(int cellID, int nx);
          ~Cell();
    private:
          int cellID_;
          int nx;
    };
  </code></pre>
  
  <p>The first way:</p>
  
  <pre><code>  Cell::Cell(int cellID, int nx)
      : cellID_(cellID), nx_(nx){}
  </code></pre>
  
  <p>The second way :</p>
  
  <pre><code>  Cell::Cell(int cellID, int nx){init(cellID, nx)}
  
    void Cell::init(int cellID, int nx){
           cellID_ = cellID;
           nx_ = nx;
    }
  </code></pre>