title: Using namespace std?
body: <p>I included the line <code>using namespace std;</code>on top of my code. Now consider the declaration   <code>int a,b,c;</code>.Is above code an equivalent to <code>int std::a,std::b,std::c;</code>? If so, consider the following example:</p>
  
  <p>If I declared(defined) a namespace <code>Hi</code> after the line <code>using namespace std;</code>.
  Is <code>Hi</code> a part of <code>std</code> i.e .., am I supposed to use <code>Hi</code> as <code>std::Hi</code>?</p>
  
  <p>I'm a beginner .</p>