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<>1.基础常识
软件:就是一系列按照特定顺序组织的计算机数据和指令的集合,分为系统软件和应用软件
<>系统软件:windows,mac os, linux,unix,android,ios,…
<>应用软件:word,ppt,画图板,…
人机交互方式:图形化界面 vs 命令行方式
<>应用程序 = 算法 + 数据结构
<>2.计算机语言的发展
<>第一代:机器语言
<>第二代:汇编语言
<>第三代:高级语言
>面向过程:C,Pascal,Fortran
>面向对象:Java,JS,Python,Scala,…
<>3.Java语言版本概述
具体细节可以网上了解。这个不太重要,只要记得几个关键时间,1996年发布JDK1.0、2004年发布里程碑式版本JDK1.5,后来为了体现这个版本重要性更名为JDK5.0,2014年发布JDK8.0,是在JDK5.0以来变化最大的版本
<>4.Java语言应用的领域
>Java Web开发:后台开发
>大数据开发:
>Android应用开发:客户端开发
<>5.Java语言特点
>面向对象性:
两个要素:类、对象
三个特征:封装、继承、多态
>健壮性:
1.去除C语言中的指针
2.自动的垃圾回收机制----->仍然会出现内存溢出、内存泄漏
>跨平台性:write once,run anywhere:一次编译,到处运行
功劳归功于:JVM