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What this article shares with you is about what is JAVA and what are the characteristics of JAVA. The editor thinks it is very practical, so I share it with you to learn. I hope you can get something after reading this article.

What is JAVA?

1.Java is an object-oriented programming language. The computer language sounds abstract and difficult to understand. Now let's break down the computer language step by step to make you understand JAVA more vividly.

If programmers operate the hardware directly, they can only use machine instructions, that is, binary coding, which is a very boring, tedious and error-prone task.

With the operating system, we don't need to operate the machine directly, so we have extended machine instructions.

By using code to represent machine instructions, programmers can focus on operations without considering the specific execution process. 、

Code code, something that represents binary coding is called code, and the emergence of extended machine instructions is the beginning of the code.

With a database management system, programmers can encapsulate data information accordingly, instead of dealing with "flow"-based information or recording simple information.

There can be more complex object-based or relational data processing. Machine instructions and database language are still needed for programming.

With the emergence of high-level language, programming has changed from goal-oriented machine to goal-oriented solution, and there is no need to consider all kinds of specific operations, programmers only need to consider logical relations.

In short, a high-level language means that programmers only need to tell the computer what to do, not how to do it.

JAVA is a high-level language.

two。 Different levels of software development

Computer hardware system: provide only machine language, that is, only recognize binary coding.

Operating system resource management: machine language + generalized instructions (extended hardware instructions).

Operating system file system: machine language + system calls.

Database management system: database management language (extends the more powerful information resource management).

High-level language: problem-oriented language

3. The execution process of high-level language

Computers cannot accept and execute programs written in high-level languages

A high-level language program needs a "translator" to translate into a binary object code program that the computer can recognize. There are usually two ways to "translate".

Compilation, compilation is the installation of a pre-programmed machine language program called "compiler" in a computer. When a high-level language program needs to be executed, the compiler translates the entire "high-level language source program" into "machine language target program".

The c language, for example, is compiled into an exe executable (executable in the operating system, not on the machine).

Explain, after the high-level language enters the computer, the interpreter scans and interprets, inputs sentence by sentence and translates sentence by sentence, and the computer executes one line without producing the target program.

For example, JAVA is an interpretive high-level language.

Although the object code program is already binary coded, it can not be run yet, and it still needs to connect with the function library to become the final executable program, so the link program is also needed.

The executable program here refers to the executable program on the operating system platform, not the program that can be executed by the machine, so the "loader" is needed to finally load the memory and execute under the support of the operating system. And expand data management with the assistance of the database management system.

4. JAVA is an interpretive high-level language.

The JAVA program is first compiled into a class file through javac, and then interpreted and executed on the JVM virtual machine.

Although JAVA has a process of compilation, there is also a process of interpretation, so JAVA is an interpretive high-level language.

Interpretive high-level languages have cross-platform compatibility. What is cross-platform compatibility? That is, no matter what operating system you have, you can run this high-level language as long as you install the interpreter.

The interpreter of JAVA is called the JVM virtual machine.

Characteristics of JAVA

Object-oriented, the so-called object, refers to the encapsulation, inheritance, polymorphism and other design methods in programming.

Traditional programming advocates that the program is regarded as a collection of functions, or a series of instructions to the computer. Such programming is very painful and tedious, and error-prone.

In object-oriented programming, every object can accept data, process data, and communicate data to other objects. Therefore, each functional unit can be regarded as a "small machine", that is, an object.

Distributed, the so-called distributed, is based on the computer network, a set of programs are not all on one computing, but on multiple computing to run together through the Internet.

For example, there is a distributed relationship between client and server. JavaWeb is a typical distributed system in which users access the server on the client machine through the network.

Robustness

If a software can run correctly in different environments, it can be considered as highly portable or robust on an unused platform.

A software can recognize the wrong input, and there is a way to deal with such errors, which is called the robustness of processing power.

A software can detect its own internal design errors or coding errors and correct them for correct execution results, which is the robustness of the module level.

JAVA has good robustness.

Security.

Collector will protect your program from memory leaks. Memory leaks are dangerous and can be used by hackers to break into your computer.

Exception, any wrong code will be detected, Little Red Cross tells you that there is a mistake here, even if it is already running, it will tell you where it is wrong when there is an error.

There is no pointer. Say the important thing three times.

JAVA also has many characteristics, such as multithreading, dynamic and so on. JAVA realizes object-oriented programming very well, allowing programmers to carry out complex programming in an elegant way of thinking.

5. Summary

First of all, we should understand what computer language is: computer language is the way people communicate with computers, and programmers tell the computer what we want it to do.

What is a high-level language: because binary machine language is very tedious, we encapsulate all kinds of binary machine instructions and express them with character codes that are easy for humans to understand, so as to improve programming efficiency and reduce programming difficulty.

How the high-level language is executed step by step: in short, no matter what language, it will eventually be translated into binary machine instructions, so the execution process of the high-level language is translation and re-translation, into a binary code that can eventually be executed.

JAVA is an interpretive high-level language, which has become the most popular high-level language today because of its unparalleled advantages.

The above is what is JAVA and what are the characteristics of JAVA, the editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

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