Java how to program the 8th edition pdf

Learn JavaScript: This is how you learn it quickly & easily

10

What is Javascript? Can you eat that? No. Check out the following video to get a 5-minute introduction to the programming language to get:

What is and what does Javascript actually do?

Javascript was originally developed to make websites more dynamic. This is still done today with Javascript. Everywhere you see small menus or other functions on a website, there is Javascript behind it, only in the rarest cases can Javascript be left out.

However, Javascript is not only used as a scripting language for websites. The execution of Javascript in the browser has become so fast that you can even create 3D games that run in the browser.

If you program with Javascript, you now have the option of creating apps for all mobile platforms. These apps are then launched in a browser-like environment. If this environment is available for Android and iOS, you can write your app in Javascript and run it on both operating systems.

Javascript has become a fully-fledged programming language for creating computer programs. Javascript was originally developed to make websites more dynamic. Without this language, all websites would look like they did in 1994.

Wherever you can make small menus or other interactions with a website on a website, Javascript is behind it. Javascript can only be left out in the rarest of cases. However, it is now used not only as a scripting language for websites.

The Execution of Javascript The browser has now become so fast that you can even create 3D games that run in the browser. In the current versions, Javascript is actually called EcmaScript and belongs to the ECMA-262 standard.

What is it used for? What can you program with it?

When the Internet came into the home computer, Javascript was created to make websites more dynamic. What does that mean? Imagine your HTML page with a nice CSS design.

Your website is initially static, which means that as soon as the website is displayed in your browser, nothing changes. If you now add Javascript, you have the option of changing the HTML content and the CSS design with Javascript. For example, when you click a button, you could hide a text and load an image.

With Javascript you can change the content of a website without having to reload the website in the browser. You can change the appearance of the website with Javascript and with Javascript you can react to user input.

In everyday web life you see Javascript in action again and again: For example, Javascript can be used to check whether a password complies with a certain rule and if not, an error message is displayed.

But that's not the only purpose of Javascript. If you program with Javascript, you now have the option of creating apps for all mobile platforms. These apps are then launched in a browser-like environment.

If this environment is available for Android and iOS, you can write your app in Javascript and run it on both operating systems. You can even have these apps put in the app stores.

Cool side effect: In addition, you also have a web application that can be called up via any browser, even if you don't have a mobile device at hand.

Web apps are the next key word. Where information is more likely to be obtained from websites, web applications are in principle also websites, although they offer more options for interaction. For example, SVGator is a web application. In any case, web applications are computer programs that can be used via a browser and without having to install additional software. Another example is gmail, Google's email program that runs in the browser

A big area is video game development. Games in the browser are very popular because you can start playing very quickly in the browser. The interesting thing is that Javascript is so powerful that you can create games from 2D to Virtual Reality (here the example: escape) and you can find ready-made libraries for them to get started right away.

Desktop programs that run on your notebook, for example, can also be programmed with Javascript. There are freely available technologies on the Internet that execute your Javascript program and display it on your computer as you know it from other programs. This has the advantage, for example, that the computer's hard drive can be accessed more easily than from the browser. With these programs you can write useful tools that do your work for you.

Server programming is a particular specialty. Whenever a web application or app wants to load or save data in a cloud, you need a server that takes care of things like user management, access rights and data storage. Here, too, there are solutions that make this possible with Javascript.

Basic structure with HTML, CSS and Javascript

In principle, one can say that Javascript is a multifunctional tool with which you can really program a lot.

Javascript is pretty powerless on its own. It's only powerful when used in conjunction with HTML and CSS. Roughly speaking, you program the user interface with HTML and CSS and the behavior of the program with Javascript.

Libraries

Another benefit of Javascript is that there is a huge community of web developers who write libraries. You can usually use these libraries free of charge. The most famous libraries are Bootstrap, jQuery, NodeJs, Cordova, Phaser.io and electron.

Sounds complicated and like a lot of learning material? You will love these libraries once you realize how much work they can do for you.

Environment for programming and learning to program

The best thing about developing Javascript with HTML and CSS is that you don't have to install any additional software at the beginning, a modern browser and text editor are sufficient. In principle, you just have to learn how to program and use this knowledge with Javascript.

Let's go back to the example, then I'll show you what Javascript looks like.

What does the code look like in Javascript?

Here we see the HTML code of the website and the matching Javascript:

What you see first are the function keywords. These are function blocks that combine several program instructions into a new command. In the function start () you can see that 3 statements are being executed there.

First the function showText is executed, which can be seen below. Further commands are then executed there, which ultimately lead to the hidden text being shown on the website. The whole thing is of course not learned in 5 minutes.

The last thing to mention is that the ES5 version of Javascript was mentioned here.

Javascript is constantly evolving, which means that a new version comes out almost every year in which the language changes a little. But you can also learn EcmaScript5 first, because so far this is the version best supported by browsers.

In addition, you learned the new features very quickly once you have ES5 on it.

How do you start with Javascript?

On this website you will find the introduction to programming in Javascript. The course is divided into 10 lessons and primarily teaches the basic programming tools. Since this is done in Javascript, this is the perfect introduction.

Programming JavaScript alone is not enough to program entire websites or web applications. In order to be able to use Javascript to the full extent, you should be able to develop websites in HTML and CSS. An example: With the canvas element from HTML5 you are able to develop games in Javascript.