property-accessor

function Car() {     
  this.m_tireSize = 17;     
  this.m_maxSpeed = 250;
  this.GetTireSize = Car_get_tireSize;     
  this.SetTireSize = Car_put_tireSize;
}

function Car_get_tireSize() {     
  return this.m_tireSize;
}

function Car_put_tireSize(value) {     
  this.m_tireSize = value;
}
var ooCar = new Car();
var iTireSize = ooCar.GetTireSize();
ooCar.SetTireSize(iTireSize + 1);

function Car() {     
  this.m_tireSize = 17;     
  this.m_maxSpeed = 250;
}
var perfCar = new Car();
var iTireSize = perfCar.m_tireSize;
perfCar.m_tireSize = iTireSize + 1;