function superClass() {

  this.bye = superBye;
  this.hello = superHello;
}

function subClass() {
  this.bye = subBye;
}
subClass.prototype = new superClass;

function superHello() {
  return "Hello from superClass";
}
  
function superBye() {
  return "Bye from superClass";
}

function subBye() {
  return "Bye from subClass";
}

var newClass = new subClass();

newClass is an instance of subClass(). It was created according to subClass()'s constructor function.

How would the above example look in a class-based language? In Java, it is translated into something like that:

public class superClass {
  public superClass () {
    this.bye = superBye;
    this.hello = superHello;
  }
}
public class subClass extends superClass {
  public subClass () {
    this.bye = subBye;
  }
}

People who read this tip also read these tips:

• Changing the Font Size on the Fly
• Implementing Moving Ads
• Using Current Context to Search for DOMDocument Nodes
• Adding A Document Fragment to An XML Tree
• Implementing the OnMouseUp Event Handler