What is JavaScript?

JavaScript was introduced in 1995 as a way to add programs to web pages on the Netscape Navigator browser. The current language is adopted by all other major graphical browsers. It has modern web applications made possible application that allows you to communicate directly without having to reload a page for each action. But it is also used in more traditional websites to provide different forms of interactivity and acumen.

It's important to note that JavaScript is virtually unrelated to Java programming language. The same name is inspired by marketing considerations rather than a good assessment. When JavaScript is introduced, the Java language is heavily operated and growing in popularity. Someone thought it a good idea to try to ride this victory. Now we are stuck in the name.

a standard document was written after its adoption outside Netscape, to illustrate how JavaScript language should work to ensure that different pieces of software claimed to really support JavaScript spoke in the same language. This is called the ECMA Script standard, the ECMA International organization that fulfills the standardization. In practice, the words ECMA Script and JavaScript can be used differently; these are two names for the same language.

Some people say terrible things about the JavaScript language. Many of these things are true. It's much to do with the fact that of course I have no idea what I'm doing, but there is a real problem: JavaScript is ridiculously liberal with what it allows. The idea behind this design to program in JavaScript will be easier for beginners. In fact it makes finding problems in your programs is usually difficult because the system no longer points to you. However, this flexibility also has its benefits. It leaves the room for a lot of strategies that are not possible in more durable languages, and as you can see can be used to overcome some JavaScript shortcomings. After I got to know the language well and worked for a long time, I learned to find the really nice JavaScript.

There were several versions of JavaScript. ECMA Script version 3 is a widely supported version during the adoption of JavaScript to dominance, roughly between 2000 and 2010. During this time worked on an ambitious version 4, which provided some radical improvements and extensions in the language. Changing life, commonly used language in such a radical way politics proved difficult, and the work in version 4 was abolished in 2008, which led to much more ambitious version 5, released in 2009. Let's now is at the point where all major browser versions 5 support, the version in which this book is focused. A version 6 is finalized and some browsers begin to support the new features of this version.

Web browsers are not just platforms that use JavaScript. Some databases, such as Mongo DB and Sopa DB, use JavaScript as their scripting and query language. Different platforms for desktop and server programming, notably the Node.js project, provide a powerful environment for JavaScript programming outside the browser.