Simple Introduction
let’s Begin

quick trying

  1. apt install default-jdk
  2. write First.java with System(Class).out(field).println(function) Hello World
  3. javac First.java,it will generate First.class, it is actually java Byte Code, will been translated by JVM to native code
  4. java First to invoke JVM execute the Class file

different Editions

  1. Standard Edition(SE) : it is core java platform
  2. Enterprise Edition (EE): for very large scale and distributed systems
  3. Micro Edition(ME): subset of SE and for mobile

Most important feature

  1. Object-Oriented
  2. Core Java APIs
  3. String / Threads / Database Program

Grammer

Variables Primitive and Reference Types

script
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int x = 1;
int y = x;
x = 2;
// y still equal 1
script
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Point p1 = new Point(1, 1);
Point p2 = p1;

Casting

Numbers Strings and Arrays

Read Input