title: Is the default constructor necessary?
body: <p>What is the difference between these two?</p>
  
  <pre><code>class Class1
  {
      public int a = 1;
  }
  
  class Class2
  {
      public int a;
      public Class2()
      {
          a = 1;
      }
  }
  </code></pre>
  
  <p>If none, can I skip the default constructor and initialize my variables like in <code>Class1</code>?</p>