Java beginner must know: 11 features of the Java language

Java is a simple, object-oriented, distributed, interpretive, robust, secure, structured-neutral, portable, high performance, multi-threaded static language. So what are the features of the Java language?

1. The Java language is simple

The syntax of the Java language is close to the C and C + + languages, making it easy for most programmers to learn and use Java. Java, on the other hand, discards features that are seldom used in C + +, which are difficult to understand and confusing, such as operator overloading, multiple inheritance, and automatic coercion of type conversions. In particular, the Java language does not use pointers and provides automatic scrap collection, which makes it unnecessary for programmers to worry about memory management.

2. The Java language is an object-oriented

The Java language provides primitives such as classes, interfaces, and inheritance, and for simplicity, only single inheritance between classes is supported, but multiple inheritance between interfaces is supported, and the implementation mechanism between classes and interfaces is supported (the keyword is implements). Siandane, a lecturer in Java training, said that the Java language fully supports dynamic binding, while the C + + language uses dynamic binding only for virtual functions. In short, the Java language is a purely object-oriented programming language.

3. The Java language is distributed

The Java language supports the development of Internet applications and has a network application programming interface (Java net) in the basic Java application programming interface, which provides a class library for network application programming, including URLs, URLConnection, sockets, ServerSocket and so on. The RMI (remote method Activation) Mechanism of Java is also an important tool for developing distributed applications. If you want to learn Java can come to this group, the first is 126, the middle is 534, the last is 519, there is a large number of learning materials can be downloaded.

4. The Java language is robust

Java's strong typing mechanism, exception handling, and automatic collection of scrap are important guarantees of Java program robustness. Discarding pointers is a wise choice for Java. Java's security check mechanism makes Java more robust.

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5. The Java language is secure

Java is typically used in a network environment, and Java provides a security mechanism to prevent malicious code from attacking. Siandane, a lecturer in Java training, said that in addition to the many security features of the Java language, Java has a security mechanism (class ClassLoader) for classes downloaded over the network, such as assigning different namespaces to prevent substitution of local classes with the same name, byte code checking, and providing an The full management mechanism (class SecurityManager) lets the Java application set up Security Sentinel.

6. The Java language is architecture-neutral

Java programs (files that are suffixed with Java) are compiled into an architecture-neutral bytecode format (a file with a suffix of Class) on the Java platform and can then be run on any system that implements the Java platform. This approach is suitable for heterogeneous network environment and software distribution.

7. The Java language is portable

This portability comes from architecture neutrality, and Java also strictly specifies the length of each basic data type. Java system itself is also very strong portability, Java compiler is implemented in Java, Java operating environment is implemented with ANSI C.

8, the Java language is interpreted type

As mentioned earlier, Java programs are compiled into bytecode format on the Java platform and can then be run on any system that implements the Java platform. At runtime, these bytecode are interpreted by the Java interpreter in the Java platform, and the classes required during execution are loaded into the runtime environment during the join phase.

9, Java is high-performance

Java is really high-performance compared to those high-level scripting languages that are interpreted. In fact, the speed of Java is getting closer to C + + with the development of JIT (just-in-time) compiler technology.

10, the Java language is multi-threaded

In the Java language, a thread is a special object that must be created by the thread class or its child (grandchild) class. There are usually two ways to create a thread: one is to wrap an object that implements the Runnable interface into a thread using a constructor of type thread (Runnable), and another to derive a subclass from the thread class and override the Run method, and the object created with that subclass is a thread. It is important to note that the thread class has implemented the Runnable interface, so any thread has its run method, and the Run method contains the code that the thread wants to run. The activity of a thread is controlled by a set of methods. The Java language supports simultaneous execution of multiple threads and provides a synchronization mechanism between multithreading (the keyword is synchronized).

11. The Java language is dynamic

One of the design goals of the Java language is to adapt to dynamically changing environments. The classes required by the Java program can be dynamically loaded into the runtime environment, or they can be loaded into the network to load the required classes. This also facilitates software upgrades. In addition, classes in Java have a run-time representation that enables type checking at run time

Java beginner must know: 11 features of the Java language