title: Instance methods and thread-safety of instance variables
body: <p>I would like to known if each instance of a class has its own copy of the methods in that class?</p>
  
  <p>Lets say, I have following class <code>MyClass</code>:</p>
  
  <pre><code>public MyClass {
  
      private String s1;
  
      private String s2; 
  
      private String method1(String s1){
      ...
      }
  
      private String method2(String s2){
      ...
      }
  }
  </code></pre>
  
  <p>So if two differents users make an instance of <code>MyClass</code> like:</p>
  
  <pre><code>MyClass instanceOfUser1 = new MyClass();
  MyClass instanceOfUser2 = new MyClass();
  </code></pre>
  
  <p>Does know each user have in his thread a copy of the methods of <code>MyClass</code>? If yes, the instance variables are then thread-safe, as long as only the instance methods manipulate them, right?</p>
  
  <p>I am asking this question because I often read that instance variables are not thread-safe. And I can not see why it should be like that, when each user gets an instance by calling the <code>new</code> operator?</p>