Example of object-oriented programming in JavaScript

objectoriented.js

// Example of how one might do some object-oriented programming in 
// JavaScript. This example uses a prototype definition to present 
// a fictional application that might govern a plane taking off 
// from an airport.  Notice how the program is not just a list of 
// instructions - control often leaves the Plane object and then 
// later returns to the Plane upon some outside event or message.

// Initiates the take off process
Plane.prototype.takeOff = function() {
 this.doSafetyCheck();
 
 if(this.isSafetyVerified()) {
  taxiService.requestTaxi(this);
 }else{
  throw new SafetyException(this.getSafetyViolation());
 }
}

// Called when plane has been taxied away from gate
Plane.prototype.onTaxiComplete = function() {
 tower.queueForTakeoff(this);
}

// Tells plane when and where to takeoff
Plane.prototype.setTakeoffInstructions = function(time, runway) {
 this.runway = runway;
 setTimeout(doTakeoff, time);
}

// Called when its time to fly
Plane.prototype.doTakeoff = function() {
 this.driveToRunway(this.runway);
 
 if(runway.isClear() && runway.accept(this)) {
  this.setHeading(runway.getBearing());
  this.pushThrottle(this.throttleCallback);
 } else {
  runway.onIsClear(this.doTakeoff);
 }
}

// Called repeatedly as throttle is pushed forward
Plane.prototype.throttleCallback = function(speed) {
 if(speed >= MIN_SPEED_FOR_FLIGHT) {
  this.holdThrottle();
  this.takeFlight();
 }
}