An Object Lesson In JavaScript - Sumthing New
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You've probably already used JavaScript objects before - for example, the code

<script language="JavaScript">
a = new Image();
</script>

creates a new instance of the Image object, while

<script language="JavaScript">
x = new Date();
</script>

creates a new instance of the Date object.

JavaScript comes with numerous built-in objects, each with pre-defined methods and properties...but what if you want to roll your own?

Well, it isn't very difficult - as a matter of fact, it's almost identical to writing a JavaScript function.

<script language="JavaScript">
// object constructor
function Sumthing() {
}
</script>

You can create an instance of the Sumthing object like this:

<script language="JavaScript">
// object instance
obj = new Sumthing();
</script>

Note the all-important "new" keyword - this is how JavaScript knows that you're trying to create an instance of an object, rather than merely running a function.

The code above creates an instance named "obj" of the object Sumthing. You can verify that it is indeed an object, oh yes, by popping up an alert().

<script language="JavaScript">
obj = new Sumthing();
alert(obj);
</script>

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