title: Setter methods or constructors
body: <p>so far I have seen two approaches of setting a variable's value in Java. Sometimes a constructor with arguments is used, others setter methods are used to set the value of each variable. </p>
  
  <p>I know that a constructor initialises an instance variable inside a class once a class is instantiated using the "new" Keyword. </p>
  
  <p>But when do we use constructors and when do we use setters?</p>