Thing C Java type of language function oriented object oriented basic programming unit function class = ADT portability of source code possible with discipline yes portability of compiled code no, recompile for each architecture yes, bytecode is "wri…

引用:Java Programming Language Enhancements Java Programming Language Enhancements Enhancements in Java SE 7 Binary Literals - In Java SE 7, the integral types (byte, short, int, and long) can also be expressed using the binary number system. To specif…

import java.util.HashSet; public class JPTQuestion3 { public static void main(String[] args) { HashSet shortSet = new HashSet(); for (short i = 0; i < 100; i++) { shortSet.add(i); shortSet.remove(i - 1); } System.out.println(shortSet.size()); } } 输出:…

public class JPTQuestion2 { public static void main(String[] args) { String s3 = "JournalDev"; int start = 1; char end = 5; System.out.println(start + end); System.out.println(s3.substring(start, end)); } } 注意:这里的end是char类型,可是,输出结果和int型的end没区别.…

import javax.swing.JOptionPanepublic class welcome {public static void main(string[] arg){JOptionPane.showMessageDialog(null,“welcome to java programming!”);} } public class welcome {public static void main(string[] arg){System.out.println("welcome t…

https://docs.oracle.com/javase/7/docs/technotes/tools/windows/javac.html\ javac - Java programming language compiler Synopsis Description Options Command Line Argument Files Annotation Processing Searching for Types Programmatic Interface Examples Se…

https://blogs.oracle.com/dave/ Java Memory Model...and the pragmatics of itAleksey Shipilevaleksey.shipilev@oracle.com, @shipilev http:/www.albahari.com/threading/ http://blogs.msdn.com/b/pfxteam/ http://joeduffyblog.com/ http://blogs.msdn.com/b/toub…

This appendix contains suggestions to help guide you in performing low-level program design and in writing code.Naturally, these are guidelines and not rules. The idea is to use them as inspirations and to remember that there are occasional situation…

运行时进行编程,类似Java的反射.运行时编程和Java反射的对比如下:   1.相同点   都可以实现的功能:获取类信息.属性设置获取.类的动态加载(NSClassFromString(@“className”)).方法的动态调用   下面是iOS中涉及到的相关使用方法     类的动态加载:NSClassFromString(@“className”),方法的动态调用:NSSelectorFormString(@”doSonethingMethod:”)     常见的方法:   isKin…

Java局部变量 局部变量声明在方法.构造方法或者语句块中: 局部变量在方法.构造方法.或者语句块被执行的时候创建,当它们执行完成后,变量将会被销毁: 访问修饰符不能用于局部变量: 局部变量只在声明它的方法.构造方法或者语句块中可见: 局部变量是在栈上分配的. 局部变量没有默认值,所以局部变量量被声明后,必须经过初始化,才可以使用. 实例变量 实例变量声明在一个类中,但在方法.构造方法和语句块之外: 当一个对象被实例化之后,每个实例变量的值就跟着确定: 实例变量在对象创建的时候创建,在对象被销毁…