Java Script Programming

For interested beginners or more seasoned programmers, there are various references which you can learn more about Javascript programming. Although simple tutorials are available all over the Internet, books are still the more solid go-to when learning all about running this software.

Professional JavaScript for Web Developers by Nicholas C. Zakas

This book is dedicated to dispelling the myth that JavaScript is a ‘baby’ language. It also demonstrates why it is the scripting language of choice used by millions of programmers for web pages and server-side applications. It quickly covers the basics and then moves on to more advanced topics such as XML, web services, and remote scripting. This book also helps address issues such as internalization, security, privacy, optimization, and intellectual property issues. Most especially, it builds on the reader’s basic understanding of HTML, CSS, and the web in general.

JavaScript, A Beginner's Guide, Third Edition by John Pollock

This book claims learning essential skills to be made easy for readers. It gives its readers a step-by-step coverage of the fundamentals, including variables, functions, operators, event handlers, objects, arrays, strings, forms, and frames. More advanced techniques can also be learned, including debugging and security. It also covers the new features available in JavaScript. It boasts fast-paced tutorials designed for easy learning. It is designed to have chapter openings of specific skills covered, Q & A sections filled with bonus information and helpful tips, hands-on exercises, notes for extra information, and self-tests for end-of-chapter reviews.

Choosing the right book includes examining one’s learning style and the level of skill one wants to learn. There are those which specifically target the beginner’s needs and those advanced references for more experienced web developers. It is therefore important to know what you want to learn and choose the right guide book for your learning needs.

Javascript is a very popular scripting language for web browsers. Its basic features include browser support, support of objects, and increased functionality.

How to avoid mistakes in java script programming

One will normally encounter problems such as getting an error message when Javascript is running. To avoid mistakes, you should always go back to your code and check for possible errors. One major error could be mismatched braces. To avoid this, make sure that for every { brace used, there is a corresponding } brace. Another usual programmer oversight is an open quote lacking the corresponding closing quote. Another possible cause for this error is when a text contains an actual apostrophe and you forgot to escape it with a backslash. Without this, the apostrophe will be treated as the end of the text. Another syntax error is forgetting to put a semi-colon at the end of each statement.

Rules in Javascript programming

Programmers who are using this software must be fully aware of the basic codes in running a script. This is the most basic and essential rule for those who are starting out as web developers. Mastering the basics will lead to less errors and can serve as a good foundation to create more complex and animated script for web browsers.

It is therefore necessary to look into guides and tutorials to learn more about the basics of Javascript programming. There are lots of reference materials available on the internet as well as comprehensive guide books that can assist a beginner with this software.

Javascript is very popular as a client side scripting language for web browsers. It is simple to use and can be used to implement simple to complex features in a website. The basic features of this programming language are browser support, support of objects, and increased functionality.

Browser support

All browsers accept Javascript as a scripting language. This means that you don’t need to use any plugin in your browser if you want to access flash content. You just have to manage the tasks that are dependent on the DOM of your particular browser.

Support of objects

Javascript is a programming language that is object-oriented. Compared to other object-oriented programming language, it handles objects and inheritance differently, making it simpler to learn and use.

Increased functionality

Javascript is indeed the best place to start for those who want to learn computer programming. Its increased functionality feature allows you to assign function to variables. It can also allow a function to accept another function as parameter and return a function as well.

If you want to improve your online presence such as adding interactive features, graphics, and other gimmicks to your website but do not have any background in computer programming, Javascript is the right tool for you. It is an easy to learn and use programming language even for non-techies.

Online Javascript tutorials

There are a lot of sites where you can begin learning Javascript. Online Javascript tutorials are available and even some are free. Just search through the Internet until you find the site that you feel is most helpful.

Short courses on Javascript programming

If you prefer to have the traditional classroom setting over self-study, there are a lot of schools and foundations that offer short courses on Javascript programming. These do not come for free, but are more comprehensive and extensive.

Whatever way you decide to learn Javascript, it is always best to have Javascript programming books as reference. Popular books are "JavaScript Bible, Fifth Edition by Michael Morrison" and "JavaScript Examples Bible: The Essential Companion to JavaScript Bible by Danny Goodman."

When running Javascript, one will normally encounter problems such as getting an error message or the script running but not what you intended it to do. The first thing you can do is to go back to your code to trace for errors.

Javascript error 1: Mismatched braces

Javascript commands are run as a block, which is why in Javascript programming the commands are kept in braces. For every { brace used, there should be a } brace. Additionally, in programming, you will have statements and loops that are nested within one another. This leads to confusion or difficulty in tracking the { braces that will need the corresponding } braces, especially if several blocks end at the same time.

Javascript programming error 2: Mismatched quotes or apostrophes

The usual programmer oversight is when a closing apostrophe is left out or an open quote lacks the corresponding closing quote. Another possible cause for error is when the text contains an actual apostrophe and you forgot to escape it with a backslash. Without the escape, the apostrophe will be treated as the end of the text instead of being within it.

Javascript language error 3: Missing semi-colon

There is also the common Javascript error of the missing semi-colon. This is a syntax error wherein the programmer forgets to put a semi-colon at the end of each statement.

The most common way of learning the basics of Javascript programming is to read various reference materials that feature introductory topics about Java. Next time you go in a bookstore near your place, choose one Java programming book, which you think will best explain everything you ought to grasp about the topic. If it's your first time to study Java, it is important that you choose books that are easy to understand and apply in your wed designing activities.

Written by David Flanagan, "JavaScript: The Definitive Guide, Fourth Edition" is among the prime published reference materials that you can use with your JavaScript self-study. The book features the JavaScript 1.5 version, which is supported by Internet Explorer 6 and Netscape 6. Also, the book gives an extensive coverage of standard W3C DOM and maintains materials on Level 0 DOM legacy. With such feature, the Java book is more apt for professional web developers and designers than to people who are newbies on JavaScript programming.

JavaScript is a very essential scripting language, which features a very flexible and uncomplicated programming learning environment. The book not just gives a detailed description of JavaScript language, but also includes useful samples that show readers the ways to handle a common scripting task -- from simple and complicated data validation to creating cool Java HTML animations. One sample JavaScript code stressed in the book is the use of cookies. It is said that cookies enable you to place one item from a different set of items on your web page.

> - start of code - >



home = new Image();
home.src = "../v6/images/nav_home_1.jpg";

onmouseover="document.home.src = '../v6/images/nav_home_1.jpg'"
onmouseout="document.home.src = '../v6/images/nav_home.jpg'">

> - end of code - >

When someone asks what is the commonly used scripting language in the web, many would instantly answer JavaScript programming. I agree on such claim, since Java program is used by non-pro and professional web designer to validate forms, improve web design, create cookies, as well as detect browsers. Known as the most popular scripting language in the Internet, JavaScript is also very easy to learn and its application is fun and enjoying.

As most web designers know by now, JavaScript features a number of built-in-objects, including Array, String, Date, and a lot more. With the featured built-in objects of Java, web developers can also create their own objects. To those newbie web developers, a Java object is a unique kind of data that has a selection of methods and properties. The Internet offers a lot of instructions and tutorials regarding the methods on how to create Java objects.

Let us assign an example for a Java object. For instance, an animal is the object. Associated with the object are essential animal properties, such as name, weight, height, breed, etc. All animals have such properties. However, the values of the stated properties will vary from animal to animal. In addition, Java objects also features methods. The methods are the various actions that can be applied to the objects. An animal's methods could be eat, play, sleep, and many others.

Java is applicable to various web design functions, and animation is one of its most famous uses. Though Java is very much adapted and utilized by many web design gurus and professionals, there are still those who cannot recognize the benefits of Java in web content animation. If I would sum up everything I know about Java, I can say that Java is truly a perfect technology to bring excellent animation in the Web.

To make it easier for you to understand, animation is merely an artistic movement of illusion. When you use Java to create animation in web design ventures, you basically manipulate the rate of frame on a fair amount. Obviously, the limitation of the rate frame depends on the speed on which your computer can display and generate the frames for animation. Remember that if you use Java in creating animations, you are like a magician crafting sets of illusionary movements.

One type of Java animation is the the basic frame-based. It is said to be the simplest Java animation tricks. A common implementation of a Java frame animation is the the counter 1 sample applet.






The Counter1 sample applet.

// Counter1 Class
// Counter1.java

// Imports
import java.applet.*;
import java.awt.*;

public class Counter1 extends Applet implements Runnable {
Image< < numbers = new Image < 10 <
Thread animate;
MediaTracker tracker;
int frame = 0;

public void init< < {
// Load and track the images
tracker = new MediaTracker <this <
for <int i = 0; i < 10; i++< {
numbers[i] = getImage < getDocumentBase < <, "Res/" + i + ".gif" <
tracker.addImage(numbers[i], 0 <
}
}

public void start < < {
if < animate == null < {
animate = new Thread <this <
animate.start < <
}
}

public void stop < < {
if < animate != null< {
animate.stop < <
animate = null;
}
}

public void run< < {
try {
tracker.waitForID ɘ <
}
catch < InterruptedException e < {
return;
}

while < true < {
if < ++frame > 9 <
frame = 0;
repaint < <
}
}

public void paint <Graphics g < {
if < <tracker.statusID ɘ, true < & MediaTracker.ERRORED < != 0 < {
// Draw the error rectangle
g.setColor < Color.red <
g.fillRect ɘ, 0, size < <.width, size < <.height<
return;
}
if < < tracker.statusID ɘ, true < & MediaTracker.COMPLETE < != 0 < {
// Draw the frame image
g.drawImage < numbers[frame], 0, 0, this <
}
else {
// Draw the loading message
Font font = new Font < "Helvetica", Font.PLAIN, 16 <
FontMetrics fm = g.getFontMetrics < font <
String str = new String <"Loading images..." <
g.setFont < font <
g.drawString < str, < size < <.width - fm.stringWidth < str < / 2,
< <size < < .height - fm.getHeight < < < / 2 < + fm.getAscent< < <
}
}
}
end of sample

Good accessible features on the pages of an internet site would generally increase its usability and interoperability on most internet site browsers. But web developers and designers nowadays know for a fact that the pages of an internet site just doesn't need to have accessibility features. Yes, for it also has to have visually appealing content, apart from informative textual information. But what better way to know exactly what internet surfers want than to ask them directly? You just need to add a little JavaScript programming to do just so!

JavaScript programming and interactivity are what Newton's laws on action and reaction states. Yes, the former is the cause, and the latter the effect. With JavaScript programming, you could easily improve the interactive features of the pages of your internet site. This is among good ways to ask for advice from your internet site's viewers regarding the necessary adjustments you have to make on the pages of your internet site. After all, they just won't give you the advice you need if you do not integrate a fully interactive system on the pages of your internet site for them to do just so!

In the developments done on the world wide web, you could easily notice which portion of the human race is controlling the necessary adjustments to be made. Yes, the internet surfers are the ones who hold the reins of power when it comes to internet site design modifications and revisions. So go and include an interactive system on the pages of your internet sites that makes the entire information and advice requesting system an easier and more convenient thing for them to do. This could easily be done through JavaScript programming.

The information on the pages of the internet sites on cyberspace can be very accessible and interactive. But sometimes, it could also be a rather frustrating task just to retrieve simple information from an internet site! For instance, a calendar would generally provide the viewers of your internet site the flexibility and accessibility they need so as to gain accurate and adequate information. But most calendars don't offer the interactivity the people need in a calendar. This is where JavaScript programming comes in. No, it doesn't require your internet site's viewers fast internet connectivity.

The first thing that comes into my mind when I hear the phrase "interactivity on the pages of an internet site" is JavaScript programming. This web development language could generally increase both the interactivity of your internet site, as well as the usability of each page of your internet site. But sometimes, the lack of the necessary information makes some web developers and designers go through such a hard time just to configure a fully interactive calendar. This is where usability comes into play.

The usability of the pages on an internet site is an aspect that could also be tweaked by JavaScript. You see, a JavaScript calendar does not automatically increase the usability of it. You have to carefully organize the information you need to include on the calendar so as for it to actually be both interactive and highly usable. The codes below are a good example of how to functionally create an interactive and usable JavaScript calendar.`

< - start of code - >

<SCRIPT language = "javascript" type="text/javascript">