/* Get Programming with JavaScript

 * Listing 11.10

 * A Counter constructor

 */

​

var Counter = function () {

  var counter = 0;

  this.count = function () {

    counter = counter + 1;

    return counter;

  };

};

​

var peaks = new Counter();

var climbs = new Counter();

​

​

​

/* Further Adventures

 *

 * 1) At the console prompt,

 *    call peaks.count and climbs.count

 *    a number of times.

 *

 * 2) Add a countDown method to the

 *    Counter constructor.

 *    The method should decrease the counter

 *    by 1 each time it is called.

 *

 * 3) Add a countUpBy method that counts up

 *    by a specified amont.

 *    e.g.

 *    > peaks.count()

 *      1

 *    > peaks.countUpBy(5)

 *      6

 *    > peaks.countDown()

 *      5

 *

 */