Java is a programming language that is characterized by many user-friendly properties. This has made it very popular since its release in 1995. Java can be found on almost all computers and other devices such as smartphones and game consoles. Even programming beginners can usually learn Java quickly. Also because Java was developed with the aim of avoiding frequent sources of error in other programming languages from the outset. Java is also freely available and anyone can download everything they need to program from the Internet, which continues to contribute to the popularity and widespread use of Java.
- Java is an object-oriented programming language.
- It is considered user-friendly and easy to learn.
- Java is very common around the world.
What is java
Java is one of the object-oriented programming languages. The Java programming language is based on the syntax of the C and C ++ programming languages - anyone who knows one of these languages can familiarize themselves with the other languages more quickly. In object-oriented programming languages, the programmer defines various objects and assigns them tasks. The second big part that a Java application consists of are the classes, which are the basis for the objects.
- Objects:An object in Java has a name, it has defined properties and methods – it can therefore carry out certain actions.
- Classes:They are the basis for objects, because a class defines what defines an object (its properties) and what it can do (its methods).
Object-oriented programming languages are easier to understand for most people than assembly languages, for example, because their mode of operation is based on the real world. In a programmed Java application, there are different objects that can do different things. This is set in classes and precisely defined. The programmer then gives the objects commands about when and in what order they should perform which actions.
Programming and execution of Java applications
In order to program and run a Java application, programmers do not need a specific operating system and generally not many requirements – another great advantage of Java. Anyone can download a Java Development Kit (JDK) free of charge from www.java.com. The JDK consists of the Java Runtime Environment (JRE), a Java compiler and the Java APIs.
The individual steps from programming to execution are briefly summarized:
- The programmer writes a source code with classes, objects and commands for the objects. He can use the APIs that already define many standard classes so that the programmer does not always have to start from scratch.
- The compiler then converts this source code into bytecode in an intermediate step. This is the same on all systems, so that it can theoretically be transferred to different operating systems (Windows, Linux, Mac and so on).
- The actual execution then takes over the runtime environment (also called interpreter or virtual machine), which understands the bytecode and makes it readable for the respective system. Due to the widespread use of Java, there is a corresponding interpreter for practically every operating system and every computer.
The making of Java
A group of developers invented the Java programming language on behalf of the computer manufacturer Sun Microsystems (now Oracle) between 1991 and 1992. This was initially called OAK (Object Application Kernel), but the developers had to change the name due to existing trademark rights. The first version of Java appeared in 1995. One reason for the rapid spread of the programming language may have been the integration of Java in the Netscape Navigator browser.
What is Java used for?
Because Java is used in so many programs and applications, you should always install the latest update for Java on your computer. Otherwise Java can represent a security hole on the computer. However, if it is up to date, Java is considered safe.