First lesson: Beginning to know Java

On the May 23, 1995, there was a great man who had done a great deed. He's James. The father of Gosling,java! That day, he announced the official birth of Java technology to Sunworld's audience.

From 1995 to now, the Java language has been evolving for more than 22 years, and the version has reached 1.8. Although not a big number, the Java language is a well-known thing in the industry. And since 2002, the Java language has dominated the world's programming language rankings, and has been at the top of the list for almost a year.

Java as a programming language, a very advanced language, there must be an excellent place: as a "object-oriented" high-level language, object-oriented is an essential feature. The simplicity of the Java language is a key advantage compared to other languages. Simple, there will be more people to learn java.

The dynamics of Java language is a very important feature compared to the rigidity of C language. and the C language and memory are closely related, Java idle and security. Performance is an important indicator of a language, high-performance Java and over 200,000 running on the very slow of the C language compared, is undoubtedly an overwhelming advantage, and compared with other languages, Java portability is a very critical breakthrough.

Compared to other advantages, Java's cross-platform is the most critical place for Java to occupy the top of the world's programming language. Whether it's a Linux operating system, a Windows operating system, or a Unix operating system .... Java will be able to run on the content written in the source file. There will be no errors in other languages or at all to run at all.

Java's unique way of running and unique running processes is the root cause of the cross-platform Java implementation. Java Virtual machine, a very critical thing, Javaapi, is also a very critical thing. It is with these two things that we realize the cross-platform of Java.

As the program runs, Java virtual machines and Javaapi isolate Java programs from the underlying hardware, and before they run, there will be some change in the way that it can make itself cross-platform. When the Java source file is written, it is compiled into a byte-code file that ends in. Class, also known as an intermediate language, in which Java can achieve cross-platform.

　　

First lesson: Beginning to know Java