chapter12/dogCatcher.html

<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Dog Catcher</title>
<script>

function dogCatcher(obj) {
	if (obj instanceof Dog) {
		return true;
	} else {
		return false;
	}
}

function Cat(name, breed, weight) {
    this.name = name;
    this.breed = breed;
    this.weight = weight;
}
var meow = new Cat("Meow", "Siamese", 10); 
var whiskers = new Cat("Whiskers", "Mixed", 12); 

var fido = {name: "Fido", breed: "Mixed", weight: 38}; 

function Dog(name, breed, weight) {
    this.name = name;
    this.breed = breed;
    this.weight = weight;
    this.bark = function() {
        if (this.weight > 25) {
            alert(this.name + " says Woof!");
        } else {
            alert(this.name + " says Yip!");
        }
    };
}
var fluffy = new Dog("Fluffy", "Poodle", 30);
var spot = new Dog("Spot", "Chihuahua", 10);
var dogs = [meow, whiskers, fido, fluffy, spot];

for (var i = 0; i < dogs.length; i++) {
    if (dogCatcher(dogs[i])) {
        console.log(dogs[i].name + " is a dog!");
    }
}

</script>
</head>
<body>
</body>
</html>