Java or javascript which is more in demand. Making a directory for the project

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What is Java What is JavaScript Why was JavaScript called that way? How Java was created What is the difference between Java and JavaScript

Let's start with what Java and Javascript are.

What is Java?

Java is a language for creating programs, a computing platform. Those. a program that processes byte codes and passes interpretation instructions to the hardware. Sun Microsystems was founded in 1995. Java Application is a special bytecode that runs on any computer using a Java virtual machine.

Therefore, many websites cannot work without Java. Java itself works quickly, has a good level of security and reliability. Java is everywhere - in game consoles, in our phones, even in the computer data center. Java is also absolutely free, you can always update it to latest version, which by the way they say should always be done.

What is Javascript?

Now let's look at what Javascript is. Javascript is a multi-paradigm website creation language. It includes styles such as imperative, functional, and object-oriented. That is, it is needed to create “live” websites. Unlike Java, Javascript was invented by Netscape, Inc. This means that it is not related to the Java platform in any way.

Today Javascript is a safe language for creating websites for general purpose. It does not work with low-level tools for working with memory and process, because was configured on the browser from the very beginning.

Why was Javascript named this way?

Earlier we found out that Javascript was created by completely different people. So why does it still have a similar name?

This is due to the fact that the language was very well known then Java programming, so they decided to cheat and called it JavaScript. They originally called it LiveScript. These people planned for him to be Java's little brother. But now everything is completely different, Javascript has grown highly, and now does not depend on or has anything to do with Java.

It was stated above that Javascript should only be used in browsers, but now JavaScript is also used on the server, today it can be used everywhere.

How was Java created?

From the beginning they planned to call it Oak. James Gosling created Java as a program for programming everyday electronic devices. After renaming Oak to Java, they decided to use it to write client applications and server software. They decided to name it after coffee "Java". That is why the language emblem shows a cup of hot coffee.

Let's look at the main differences.
Java is expressed as an object-oriented language for writing various programs. But Javascript is a functional language for producing scripts.

Unlike Javascript, which runs primarily in the browser, Java is needed for programming various applications, which run on a virtual machine.

Javascript is usually rendered as written, and java code needs to be compiled.

For them, you need to connect modules that are different from each other.

I assume that this article was very informative and interesting for readers.

LiveScript, ECSMAScript = JavaScript

Now we react calmly to Gmail, with its pop-ups, instant messages and all this without reloading the page. But in the early 90s, programs for Windows could do this, and then with a very big stretch, while imposing their nature as Standalone applications. Actually, the identified problem is the lack of interactivity on web pages, only dry text with pictures and hyperlinks. The engineers of the then Netscape company (now Mozilla) were concerned about this problem, and here it is worth starting the story about Javascript.

The young engineer Brendan Icke was given the task of creating a language that would be similar to Java, but would be smaller and, as the author himself wrote, “like his younger brother,” and very importantly, would have an expressive vocabulary so that non-programmers could quickly master the technology . After 10 days, the first version of the language was written, which they decided to call LiveScript. Of course, it is hardly possible to create an ideal language in a short period of time, but, despite some of its shortcomings, it solved the task assigned to it, namely, it allowed you to work with HTML without reloading the page.

After some time, the language was renamed JavaScript. This name was not chosen by chance. At that time, and actually like now, Java language was very popular and the prefix of the word Java was supposed to attract more attention to the language. And it bore fruit, people became interested, tried it, appreciated the capabilities of the language, so much so that after the announcement of the technology, more than 20 companies expressed their intention to use Javascript in their future products as an object scripting language with open standard(based on Wikipedia). And this was 1995.

In the same year, at the request of Netscape, the language was standardized by the ECMA (European Computer Manufacturers Association) and received the name ECMAScript. The current version of the document is 5.1, which is supported by most modern browsers.

Now this creates confusion, people sometimes get confused about the names LiveScript, JavaScript and ECSMAScript. But if we omit the difference between the concepts of a standard and a programming language, then there is no difference as such; history and corporations have decreed this.

Vital Concepts for Your Code

Javascript has grown a lot since 1994. Now this is a fullstack language and this means that you can write a full-fledged website on it, without using additional server language programming, for example. This became possible after the appearance of the V8 engine developed by Google And server platform node.js based on it.

It is worth highlighting two very important features of the language: closures and execution context.

Closures are the ability to access variables that are available at the function declaration location;
Execution context is where the this reference changes to objects within a function, depending on who the function is being executed for.

These are quite easy and at the same time complex concepts, the understanding of which comes with practice. But misunderstanding them is the most common cause errors in the code.

JavascriptThisJava?

Perhaps the most common question on the Internet. As you already understand, the answer is negative. The similarity in name is just a marketing ploy. JavaScript inherits some features from Java, but nothing more. The table describes the most obvious differences.

Javascript
Interpretable		Compiled
This means that the code you write in Javascript can be executed immediately, without compilation. In turn, the Java code must first be converted into bytecode, which is subsequently executed by the virtual machine.
Dynamic typing	Static
Dynamic typing means that in different parts of the program, the same variable can take on values various types. For example, when declaring a variable, you defined it as a string, but during execution, you assigned it numeric value. Javascript interprets such code without errors, but the Java compiler will throw an error.
Prototypically object-oriented	Class Object Oriented
In Javascript, the core element is prototype objects, which can change as the program runs and be cloned to create other objects. This is the so-called prototype programming. There are two key concepts in Java, class and object. Before an object can be used, it must be described as a class. This is the so-called class-based prototype programming.

To summarize. Where to begin?

JavaScript in this moment, the most popular client programming language. If you have previously heard about it and, after reading the article, decided to study it, ProstoWeb has prepared several for you useful resources for beginners:

Websites

http://javascript.ru – number one in RuNet;
https://developer.mozilla.org/ru/docs/JavaScript - the most latest information according to the most current topics language. Most of the articles cover deeper topics, but there is also basic information on the language (English).

According to Github statistics, at the moment, Java and JavaScript are the most popular programming languages, after Python, PHP and Ruby. Despite the similarity in their names, this is very different languages. You might think that JavaScript is a simpler, lighter Java version. But you are wrong. These are two completely different full-fledged programming languages that allow you to do different things, but at the same time they have more differences than similarities.

In this article we will look at the difference between java and javascript to help you choose exactly the language that you need. fits better everything to solve your problems. As you will see, both languages are very rarely used to perform the same tasks.

The first version of Java, codenamed "Oak" and "Green" after initial development, was released in May 1995. Many programmers at the time regarded this language as a replacement for C/C++ because it had similar syntax and also introduced new concepts. The language made programming easier and safer.

One of the core principles of Java, which began then and continues today, is the idea that programmers can write code once and use it everywhere. Unlike compiled executable files who have different format For different platforms, Java code is compiled into a single JAR file that can be run in any Java-enabled environment.

This is made possible by the Java Machine (JVM). Java machine, this is a common program that acts as an intermediary between operating system And Jar file. It reads a program file that contains Java instructions and turns them into instructions for the platform on which it runs at runtime. This process is called Just-in-time compilation or JIT.

What is JavaScript?

JavaScript emerged as a simple language for creating constraint HTML forms. When Netscape Communications decided they needed a more dynamic Internet, they created new language, which could be used directly inside HTML. This language was called LiveScript and was developed in ten days.

The language then developed for some time under this name, but then several reasons appeared to change the name. Firstly, JavaScript and Java were supposed to complement each other, so JavaScript received a similar syntax, and secondly, at that time Java was very popular, and therefore developers, to attract more people to the language they decided to use a well-known word in the name and replaced Live with Java. This is how JavaScript was born. But only the syntax is similar in languages; later, Java was used less and less on the Internet and the languages diverged their paths. Nowadays HTML, CSS and JavaScript are the main components of web development.

Unlike Java, which is compiled, JavaScript is a completely interpreted language. When you visit a site that uses JavaScript, your browser receives full source programs. Then it is executed on the fly with using JavaScript engine. Various browsers They use different engines: V8 (Chrome), SpiderMonkey (Firefox), Chakra (Edge) and so on.

Similar aspects of Java or JavaScript

Despite all the differences, these languages have several similarities that can be considered even if you do not intend to use both languages for web development. Here are the main ones:

Objectively oriented programming(OOP)- both languages require the programmer to use the principles of objects and the relationships between them during coding. Both languages support OOP patterns such as interfaces, encapsulation, and polymorphism.
Forend development- both languages can be used to develop a forend, in other words - a user interface that works together with the server. JavaScript can be embedded in HTML, or as a third-party library on site pages. And Java can run in a browser in as java applet.
Backend development- in other words - development of server software. Java has long been used in backend technologies by Apache, JBoss, and WebSphere projects. New technology,Node.js allows you to run servers written in JavaScript.

Main differences between Java vs JavaScript

Initially, languages were developed to solve absolutely different tasks. Java is intended more for creating full-fledged applications, while JavaScript is a scripting language for organizing an interface on the web. Here are the main differences to make it easier to understand the difference between java and javascript:

Compilability and interpretation- as I wrote above, Java is a compiled programming language, and JavaScript is interpreted. The only difference is in the implementation; in fact, both languages can run on different platforms.
Static and dynamic type checking- Java uses static type checking. The variable's type is checked at compile time. The programmer must explicitly specify what type the variable will be - string, number, floating point number, and so on). JavaScript like others scripting languages uses dynamic typing. The correct use of types is checked at run time. The programmer does not need to specify the type of the variable when declaring it. Both approaches have many advantages and disadvantages. The most important difference between java and javascript is that with static typing, most errors appear at the development stage, because the compiler knows what to expect, the code runs faster and consumes less memory. Advantage dynamic typing- programs are written faster and easier.
Parallelism- the implementation of the ability to execute multiple sequences of instructions at the same time is very different in Java and JavaScript. Java allows you to use multiple threads to run parallel tasks. Implementing concurrency in JavaScript is very complex. It is only available in Node.js. On the main thread, this is implemented through a run queue called an event loop. Both methods work well, but Java threads faster.
Classes and objects- Java uses classes and relationships between them. The properties of an object are defined in a class and are an immutable part of the class. You can inherit classes from other classes and then they receive all the properties of their parents. You might be surprised, but there are no classes in JavaScript. There are only objects there. And inheritance is implemented differently. All objects can be inherited from other objects directly. To do this, just specify the desired object as a prototype.

When is it best to use?

As with all languages, your choice of Java vs JavaScript will depend on many factors. For example, on what you want to create and what resources you have for it. JavaScript is better suitable for web technologies, while Java is ideal for creating regular programs and anything else.

It is better to choose Java if you are developing:

Android application;
Commercial software;
Scientific computing software;
Big Data analysis software;
General purpose software or security tools;
Server programs.

It is better to use JavaScript in the following areas:

Dynamic Single Page Applications (SPA);
Fort-end applications (Query, AngularJS, Backbone.js, Ember.js, ReactJS);
Server applications (Node.js, MongoDB, Express.js and so on);
Mobile applications (PhoneGap, Ract Native, etc.).

conclusions

In this article we looked at how java differs from javascript. As you can see, there are simply a lot of differences, despite the fact that the languages have a similar name. The question of which is better than java or javascript is difficult to answer, because languages have very different areas applications. I hope this information was useful to you.

To conclude, a video joke about the confrontation between Java and JavaScript based on Game of Thrones:

Java and JavaScript are programming languages used to develop applications or functions on web pages. Their code has some similarities, but there are differences between them.

These languages are now relevant and very often used. These are not the newest languages, but you can’t even name them.

The biggest difference between these languages is the type of applications they create. When programming in Java, they will either run from the desktop or be initiated into a web page. In most cases, applications created in such a language are self-contained and can be opened as a normal program window. For their Java works must be installed on your computer. But JavaScript comes with everything modern browsers, and as long as it is enabled, its code will be executed when the web page loads.

Language JavaScript programming commonly used in web development and provides additional functions pages or can create an application within the web page itself. Some video games have been developed with using JavaScript, and they can be launched directly in the Internet browser window. For example, on the gaming site for children http://igryman.ru/view_360 JavaScript is used for the functionality of the site, and the games themselves are made in Flash.

Java programs typically perform calculations and basic intelligence on the server side or in a Java applet, which must be loaded first. JavaScript, on the other hand, performs calculations and “thinks” always on the client side, the computer where the web page is open. For this reason, JavaScript is often faster, sometimes almost instantaneously. Java applications take a little longer to process.

Java programs can sometimes require a lot of computer memory to function, which can cause the computer or other programs to slow down. While Java can be used to create very powerful things, its higher memory consumption is its downside. JavaScript, however, uses less memory (in some cases very little) to perform processing and functions properly. This mutual language programming used in many web pages today (including this one) due to its low memory requirements and ability to provide many various functions on the web page.