Java Script

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What does JavaScript mean?

JavaScript is a well-known and widely used programming language. Originally, this programming language was implemented as part of web browsers to enable client-side scripts to interact with the user, control the browser, communicate asynchronously and change the displayed document content. However, the language has now evolved to such an extent that it is also used for the creation of desktop applications and in the field of game development.

The main features of the key design within JavaScript were adopted from the programming languages Self and Scheme. It is a so-called multi-paradigm language, which allows not only object-oriented, but also imperative and functional programming methods. With the help of the ECMA script programming language standards, JavaScript was formalized and generally used as part of this web browser. This is called client-side JavaScript. This enables programmatic access to objects in a host environment.

JavaScript is a prototype-based scripting language that is also type-safe and dynamic and has certain first-class functions. Even though JavaScript uses a large number of Java terminology standards and terms, the two languages are not linked and use completely different semantics.

Areas of application

JavaScript is used in a wide variety of areas. The dynamic manipulation of websites, the so-called document-object model, is one of the most typical and most common areas. These are the possible display of dialog windows, the suggestion of search terms during text input and the sending and receiving of data.

One of the central areas of application for JavaScript is data validation when entering data into a form. This happens before the transfer to the server. JavaScript can also be used to disguise or anonymize e-mail addresses. In this way, the spread of spam can be combated. Even detaching a specific page from a complete frameset and switching between several frames at the same time is no problem.


JavaScript is always executed in a sandbox within the browser used. The scripting language can therefore, as a rule, only access the objects of the browser. Access to the file system is not possible. This prevents sensitive data from being overwritten or read. The sandbox principle can also be partially circumvented. In the event of inadequate security settings, the corresponding restriction can be overridden for JavaScript.

Misuse of JavaScript

Unfortunately, it is also possible to misuse JavaScript. Some applications are also considered to be poorly programmed and developed. Many of these critical cases can now be blocked by the browser used without any major problems.

The following are examples of such misuse:

  • Obfuscation of the source code

Obfuscating a source text makes it very difficult to read.

  • Deactivating the copy function of the browser

Copying content is made more difficult and can lead to problems for the user.

  • Deactivating the context menu

Saving an entire website or individual images is made more difficult.

  • Unwanted pop-ups / pop-unders

These are opened without consent and unsolicited. Especially in the case of advertisements, this is a particularly annoying fact for many users.

  • Opening / closing Broswer windows

Many users find the unintentional opening or closing of browser windows very annoying and extremely unpleasant.

JavaScript can also be misused by third parties. It is therefore possible that a foreign computer can be attacked via code injection. As soon as JavaScript is not activated, usability is severely restricted in many cases. Despite deactivating JavaScript, there are so-called “low-barrier” pages that can be used relatively easily and without major restrictions.

History of JavaScript

JavaScript was originally developed by Brendan Eich as part of a browser that was widely used at the time. At that time, the browser was in a fierce battle against a competitor. Eich considered a client-server solution in order to gain supremacy on the Internet. This turned out to be the best option for enforcement. Java was above all a main competitor of C++ and was particularly aimed at professional programmers, so Brendan Eich tried to develop a simple programming language. Its aim was to dispense with explicit program compilations, but also to complement JavaScript. Eich also wanted to appeal to amateur programmers.