The development of programming language first-generation languages: Machine language 0011 1100 ... Second-generation languages: assembly language ADD 12,0x13 third-generation language: has reached the advanced language stage, process-oriented language, C, Basic Fourth generation language: Object-oriented language, Java, c#,c++ Five Dynasties language: SQL statement Java was probably born in early 1995, Sun Company to publish Java to the Internet, free for everyone to use
The JDK Version 1.0 was developed in Oak, which was released in 1996-01-23.
JDK Version 1.1 was released in 1997-02-19.
J2SE Version 1.2 was developed codenamed Playground (playground) and was released in 1998-12-08. J2SE Version 1.3 was developed for the Kestrel (Red Falcon) and was released in 2000-05-08.J2SE Version 1.4 was developed for Merlin (Hayabusa) and was released in 2004-02-06 (first released under JCP). Java Version SE 5.0 was developed as Tiger (Tiger), which was released in 2004-09-30. The Java Version SE 6 was developed in Mustang (Mustang) and was released in 2006-12-11. The Java Version SE 7 Development Code is Dolphin (Dolphin), released in 2011-07-28. Java SE 8 Java 8 was released on March 14, 2014. Starting with Java 8 The development code has been deprecated, so there is no official development code since Java 8. Several versions of Java:
- Javase (J2SE) (JAVA2 Platform standard Edition,java platform version)
- EE (Java 2 platform,enterprise Edition,java Platform Enterprise Edition)
- Javame (J2ME) (Java 2 Platform Micro Edition,java Platform mini version).
Features of Java:
1.java style is similar to C + +, in a sense Java is a variant of C + + 2.java eliminate the error-prone and incomprehensible pointers, structures, and memory management in C and C + + 3.java provides a rich library of classes, easy to develop programs 4.java is a fully object-oriented language that supports object-oriented features such as inheritance, overloading, polymorphism,; & nbsp C + + is an object-oriented and process-oriented mixed language, C is a purely process-oriented language 5.java is a strong type of language that is stricter than C + + Check, Java case-sensitive letters 6.java provides an automated garbage collection mechanism GC that effectively avoids C, C + + memory leak issues 7.java prohibits unauthorized access to memory because Java does not have pointers, memory requests and releases 8. Cross-platform, Java source code compiled into a structurally neutral intermediate format, this format is machine independent, as long as the JVM (Java Virtual machine)   are installed; Computers can run this machine-independent intermediate file,. class, Java compile once, run everywhere 9. For different operating systems, there will be different Java virtual machines, which will also determine the portability of Java 10. java support multi-threading, simple understanding, if it is a single core CPU, then through the time slice rotation, multi-threaded execution program, If you have a multicore CPU, then you can Understood as two or more threads running at the same time
Features and development of Java
