the origin and development of Java
The development of programming language first generation language: Machine language 0011 1100 ...
Second generation languages: assembly language ADD 12,0x13
third-generation languages: Advanced language Stage, process-oriented language, C, Basic
Fourth Generation Language: Object-oriented language, Java, c#,c++ Fifth generation Language: SQL statements
Java was probably born in early 1995, Sun Company Java published to the Internet, free of charge for everyone to use
January 23, 1996, Sun released the JDK1.0
more about the history of Java, here is not too much to introduce ...
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 discarded C, C + + easy to throw errors and incomprehensible pointers, structures, and memory management, etc.
3.java provides a rich library of classes, very convenient to develop programs
4.java is a fully object-oriented language that supports object-oriented features such as inheritance, overloading, polymorphism, etc. C + + is an object-oriented and process-oriented mixed language, and a pure process-oriented language 5.java is a strongly-typed language that is more rigorous than a C + + check, and Java is case-sensitive with uppercase and lowercase letters
6.java provides the automatic garbage collection mechanism GC, effectively avoids C, C + + memory leak problem
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 structure-neutral intermediate format, this format is machine-independent, as long as the JVM (Java Virtual machine) installed
computer, you 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 .Java supports multi-threading, simple understanding, if it is a single-core CPU, then through the time slice rotation, multi-threaded execution program, if it is multi-core CPU, then you can understood as that two or more threads run concurrently
From for notes (Wiz)
The origin and development of Java
