Creating Simple ActionScript 2.0 Classes - Page 6

Examining The class_basics.fla:

So the code we used in the class_basics.fla was:

var bill = new Person("Bill");
bill.sayHello();
var jane = new Person("Jane")
jane.sayHello();
var pat = new Person("Pat");
pat.sayHello();

Basically, we did the same two things three time.

First:

var bill = new Person("Bill");

Creates a new instance of the person class. The instance name is the variable name (bill). Notice that we use the new keyword to call the Person function. We pass the string "Bill" to the Person constructor, and hence the _myname variable in the bill instance of the Person class gets set to bill. The same thing is occurring each time we use the new keyword:

var jane = new Person("Jane")
var pat = new Person("Pat");

So in total we end up with three instances of the person class (bill, jane, and pat). Now, notice that we passed each new Person() a different string. ("Bill", "Jane", and "Pat" respectively). We can do this because each instance of the class gets its own copy of the _myname variable. This is how we can have one class file, but have different states in each instance. We can see the effect of this when we call the say hello method:

bill.sayHello(); traces "Hello, my name is Bill"
jane.sayHello(); traces "Hello, my name is Jane"
pat.sayHello(); traces "Hello, my name is Pat"

This happens because the value of _myname is different for each instance of the Person class event though we are calling the same method.