JavaScript Basics: Difference between revisions

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== Prototypes ==
== Prototypes ==
Every object has a <code>prototype</code> property.
<pre>
<pre>
Counter.prototype = {
Counter.prototype = {

Revision as of 17:01, 18 April 2015

Link to external Javscript file

<head>
	<title>Test</title>
	<meta http-equiv="content-type" content="text/html;charset=utf-8" />
	<script src="spectra.js" type="text/javascript" ></script>
</head>

Types

The built-in types are string, number, boolean, null, undefined, object.

Use typeof some_var to get the type.

The following are considered false: false, 0, "", null, undefined, NaN.

Arrays

Arrays are special objects.

var my_array = [];    // make a new array

Strings

"  Hello  ".trim()      // "Hello"

Objects

var new_object = {};              // make a new empty object
new_object.name = "Bill";         // create a property
new_object["name"] = "Bill";      // same thing
for (var key in my_object){       // iterate over an object
    // do something with key
    // value is my_object[key]
}

Prototypes

Every object has a prototype property.

Counter.prototype = {

};