example of what a constructor is

example.java

class Example {
  /*
  A car has the following attributes:
   1) number of wheels
   2) tire type

  A car has the following behaviors:
   1) it can run at a certain speed
   2) it can park
  */
  static class Car {

    private String tireType = "Nokia@N";  // Nokia@N

    // An example of "constructor"
    // A constructor has the following properties
    // 1) It looks like a method  
    // 2) But, it's special in that the "method name"
    //    is the same as the class name. e.g. Car
    // 3) Yeah, it looks like a method, but it has
    //    NO "return type"
    // 4) Constructor is special because it's always
    //    run when the class is "new"ed (e.g. object instantiation)
    
    private int numWheels = 18;          // 18

    // Constructor choice when no input parameter    
    Car()
    {
      numWheels = 8;
    }  
    
    // Constructor choice when there is an input parameter of type int
    Car(int inputNumWheels)
    {
      numWheels = inputNumWheels;
    }
    public int getNumWheels()
    {
      return numWheels;
    }
  };
  
  
  public static void main(String[] args) {
    Car car1 = new Car();  // an example of object instantiation
    Car car2 = new Car(10);   // another object instantiation
    System.out.println(car1.getNumWheels());    
    System.out.println(car2.getNumWheels());    
  }
}