Characteristics of java language:
1. Simplicity
Java seems to be well designed Much like C, but in order to make the language small and familiar, the designers removed many of the features available in C that are rarely used by average programmers. Java also eliminates C's operator overload (overload) and multiple inheritance features, and does not use the main file, eliminating the need for preprocessors. Because Java has no structures, arrays and strings are objects, so no pointers are needed. Java can automatically handle object references and indirect references and realize automatic collection of useless units, so that users do not have to worry about storage management issues and can spend more time and energy on research and development.
2. Object-oriented
JAVA itself is a purely object-oriented programming language. Object-oriented is the foundation of JAVA and an important feature of JAVA. JAVA advocates that everything is an object. In the syntax, individual data and functions cannot be defined outside the class. The outermost data type of the JAVA language is an object, and all elements can be accessed through classes and objects.
3. Distribution
The distribution of JAVA includes operation distribution and data distribution. Operation distribution refers to arranging related operations on multiple different hosts, while data distribution refers to dividing data separately. Stored on multiple different hosts, which are different members of the network. JAVA can access network objects through URL (Uniform Resource Locator) objects in the same way as accessing the local system.
4. Compilation and Interpretability
The Java compiler generates byte-code (byte-code) instead of usual machine code. Java bytecode provides an architecture-neutral object file format, and the code is designed to efficiently deliver programs to multiple platforms. Java programs can run on any system that implements a Java interpreter and run-time system.
In an interpreted environment, the standard "linking" phase of program development largely disappears. If Java still has a linking stage, it is just the process of loading new classes into the environment. It is an incremental and lightweight process. Therefore, Java supports rapid prototyping and easy experimentation, which will lead to rapid program development. This is an elegant development process that contrasts with the traditional, time-consuming "compile, link, and test."
5. Robustness
One of the design goals of JAVA programs is to write multi-faceted and reliable applications. JAVA will check for errors during compilation and runtime of the program. and eliminate errors. Type checking can help users detect many errors that occur early in development. The emergence of integrated development tools (such as Eclipse, NetBeans) also makes it easier to compile and run JAVA programs.
6. Security
Java’s storage allocation model is one of its main ways to defend against malicious code. Java has no pointers, so programmers cannot get behind the scenes and fake pointers to memory. More importantly, the Java compiler does not handle storage arrangement decisions, so the programmer cannot guess the actual storage arrangement of the class by looking at the declaration. Storage references in compiled Java code determine the actual storage address at runtime by the Java interpreter.
The Java runtime system uses a bytecode verification process to ensure that code loaded onto the network does not violate any Java language restrictions. Part of this security mechanism includes how classes are loaded from the Internet. For example, loaded classes are placed in separate namespaces rather than local classes, preventing a malicious applet from replacing standard Java classes with its own versions.
7. Portability
JAVA programs have architecture-independent features and can be easily transplanted to different computers on the network. At the same time, JAVA class libraries also implement interfaces for different platforms, making these class libraries portable.
8. High performance
Java is a language that is compiled first and then interpreted, so it is not as fast as a fully compiled language. But there are situations where performance is critical. To support these situations, Java designers created a "just-in-time" compiler, which translates Java bytecode into machine code for a specific CPU (central processing unit) at runtime, as well. That is to achieve full compilation.
9. Multi-threading
Java is a multi-thread language. It provides support for multi-thread execution (also known as lightweight procedures) and can handle different tasks, making programming with threads easy. easy. Java's lang package provides a Thread class, which supports methods for starting threads, running threads, stopping threads, and checking thread status.
10. Dynamics
The Java language is designed to adapt to changing environments. It is a dynamic language. For example, classes in Java are loaded on demand, and some are even obtained over the network.
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