It is a programming language Developed by Sun Microsystems (James Gosling).
It is a general-purpose object-oriented language.
It is Based on C/C++
It is widely accepted by developers.
Designed for simple Web/Internet applications.
* Simple
Fixes some clumsy features of C++
* Object oriented
Focus on the data (objects) and methods manipulating the data.
* Interpreted
Java compiler generate byte-codes, not native machine code.
* Portable
Same application runs on all platforms.
* Reliable
Extensive compile-time and runtime error checking.
* Secure
Usage in networked environments requires more segurity.
* Multithreaded
Multiple concurrent threads of executions can run simultaneously.
* Dynamic
Java is designed to adapt to evolving enviroment.
* Data types
8 primitive types
boolean, byte, short, int, long, float, double, char.
Class types, either provided by Java, or made by programmers
String, Integer, Array, Frame, Object, Person, Animal,...
Array types
* Variables
Data Type identifier [= Expression ]:
* Flow of control
if, if-else, if-else if
switch
for, while, do-while
break
continue
* Slower than compiled language such as C
An experiment in 1999 showed that Java was 3 or 4 times slower than C or C++
Title of the article : "Comparing Java vs. C/C++ Efficiency
Issues to Interpersonal Issues" (Lutz Prechelt)
"Adequate for all but the most time-intensive programs."