Passing Arguments to Methods, An Example

class Car {

  String licensePlate = "";     // e.g. "New York 543 A23"
  double speed        = 0.0;    // in kilometers per hour
  double maxSpeed     = 123.45; // in kilometers per hour
  
  // accelerate to maximum speed
  // put the pedal to the metal
  void floorIt() {
    this.speed = this.maxSpeed;  
  }
  
  void accelerate(double deltaV) {

     this.speed = this.speed + deltaV;
     if (this.speed > this.maxSpeed) {
       this.speed = this.maxSpeed; 
     }
     if (this.speed <  0.0) {
       this.speed = 0.0; 
     }     
     
  }
  
}

class CarTest4 {

  public static void main(String[] args) {
    
    Car c = new Car();
    
    c.licensePlate = "New York A45 636";
    c.maxSpeed = 123.45;
    
    System.out.println(c.licensePlate + " is moving at " + c.speed + 
     " kilometers per hour.");

    for (int i = 0; i < 15; i++) {
      c.accelerate(10.0);     
      System.out.println(c.licensePlate + " is moving at " + c.speed + 
       " kilometers per hour.");
    }

  }
    
}

Here's the output:

utopia% java CarTest4
New York A45 636 is moving at 0.0 kilometers per hour.
New York A45 636 is moving at 10.0 kilometers per hour.
New York A45 636 is moving at 20.0 kilometers per hour.
New York A45 636 is moving at 30.0 kilometers per hour.
New York A45 636 is moving at 40.0 kilometers per hour.
New York A45 636 is moving at 50.0 kilometers per hour.
New York A45 636 is moving at 60.0 kilometers per hour.
New York A45 636 is moving at 70.0 kilometers per hour.
New York A45 636 is moving at 80.0 kilometers per hour.
New York A45 636 is moving at 90.0 kilometers per hour.
New York A45 636 is moving at 100.0 kilometers per hour.
New York A45 636 is moving at 110.0 kilometers per hour.
New York A45 636 is moving at 120.0 kilometers per hour.
New York A45 636 is moving at 123.45 kilometers per hour.
New York A45 636 is moving at 123.45 kilometers per hour.
New York A45 636 is moving at 123.45 kilometers per hour.

Previous | Next | Top | Cafe au Lait

Copyright 1997-1999 Elliotte Rusty Harold
elharo@metalab.unc.edu
Last Modified October 1, 1999