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Javascript
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Javascript Tutorials and Reference Guides Aren't Just the Stuff of a Computer Science Degree

Any guess what electronic medical billing, computer programming classes, and elementary education degrees have in common? It's JavaScript. In fact, just about anything that has anything to do with the internet relies on Javascript at one point or another.

It may take a computer science degree to master the programming language but most of the rest of us use Javascript every time we turn on a computer. Web pages, internet searches, PDF documents, widgets – yep! They all use Javascript.
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The good news is that we don't have to understand it to enjoy Javascript. It's pretty much like electricity: we know how to flip a switch to turn an electric light off or on even though we don't need to know the hows and the whys behind the action. And, very much like electricity, some people want to know more about JavaScript.

If that's you, remember these Javascript tutorials and reference guides aren't just the stuff of a computer science degree. Think of them as an introduction and, if you like what you learn, there's no reason not to enroll in some computer programming classes or work toward a full-fledged computer science degree. You'll discover skills you can put to use in any industry you choose to enter.

Introduction

JavaScript is a scripting language created by Netscape in the late 1990s. Originally it was called LiveScript but, given the popularity of the Java programming language at the time, Netscape renamed it JavaScript hoping to capitalize on the name. In reality there are very few similarities between the two, and while JavaScript became popular the name has done little more than confuse.

Four features of JavaScript

Operators

Like most languages JavaScript has operators for comparing, and modifying data. Many of JavaScripts operators are C-Like. Similar to C parentheses can be used to group operations, though without parentheses JavaScript uses an order of operations similar to that of C, which derives from operator precedence in mathematics. JavaScript also uses short circuit evaluation in comparisons. If the first part of a JavaScript statement would make certain that the whole statement would be either true or false then the remaining portion of the statement is skipped. The following are some of JavaScript operators.

Assignment Operators

Comparison Operators

Arithmetic Operators

Bitwise Operators

Bitwise operators act on bits in memory, and treat variables as though they were binary numbers. This allows bitwise operators, like those from Assembly language, to be implemented in JavaScript programs.

In addition to the above operators, JavaScript has some special operators that are unable to be classified separately.

Statements

Outside of using the comma operator, all JavaScript statements are separated by semi-colons, which is a common feature of c-like languages. This remains true even if multiple statements appear on the same line, or within an HTML event like the onClick handler. At the same time, because statements are delimited by semicolons, a single statement can span multiple lines which is often useful for making complex statements easier to understand and properly document. 

Core Objects

There are a few core objects, and data types which are commonly used in JavaScript scripting.  JavaScript being object oriented all data types act as objects and complex datatypes, like strings, inherit properties from simple objects like arrays. Complex objects can inherit the properties of multiple simple types as well. 

Document

Document properties are used to access the HTML DOM. In inter-application scripting some of these may be re-implemented to access properties of another type of document. One of the most common uses for JavaScript is manipulating DOM objects within hypertext documents. AJAX, which utilizes JavaScript to implement advance interactivity, uses the document object.

Window

JavaScript has a separate set of objects for dealing with Windows. At first this may seem odd since there is already a document object. In fact a Window contains a Document object. The Window object deals with functionality related to or between Windows, as well as the history, and window properties like location, and size. Frames act as separate windows and have essentially the same objects.

Form

The Form object deals with the properties of HTML forms. This can be used to update forms as information is entered, or to validate what information has been entered as well as offer extra options depending what kind of data has been entered.