kavnlaputa-优快云博客

原创 Java Puzzlers笔记--puzzle 22:Dupe of URL url的使用

public class BrowserTest{ public static void main(String[] args){ System.out.println("iexplore.exe"); http://www.google.com System.out.println(":maxmize"); }} Solution: 显示：iexplor

2007-03-07 21:57:00 706

原创 Java Puzzlers笔记--puzzle 21: What's my Class, take 2 路径字符问题

package com.javapuzzlers;import java.io.File;public class MeToo{ public static void main(String[] args){ System.out.println(MeToo.class.getName().replaceAll("//.", File.separator) + ".class");

2007-03-07 11:10:00 598

原创 Java Puzzlers笔记--puzzle 20: What's my Class? String.replaceAll()的使用

package com.javapuzzlerspublic class Me{ public static void main(String[] args){ System.out.println(Me.class.getName().replaceAll(".","/") + ".class"); }}Solution: 显示：//////

2007-03-07 10:59:00 795

原创 Java Puzzlers笔记--puzzle 19: Classy Fire 注释问题

public class Classifier{ public static void main(String[] args){ System.out.println(classify(n) + classify(+) + classify(2)); } static String classify(char ch){ if("01234567

2007-03-07 10:42:00 901

原创 puzzle 18: String Cheese String的构造

public class StringCheese{ public static void main(String[] args){ byte[] bytes = new byte[256]; for(int i = 0; i bytes[i] = (byte) i; String str = new String(bytes); for(int i = 0; i System.

2007-03-05 23:06:00 636

原创 Java Puzzlers笔记--puzzle 17: Huh? 转义字符问题

Is this a leage Java Program? if so, what does it print?/u0070/u0075/u0062/u006c/u0069/u0063/u0020/u0020/u0020/u0020/u0063/u006c/u0061/u0073/u0073/u0020/u0055/u0067/u006c/u0079/u007b/u0070/u0075/u0062

2007-03-05 22:57:00 674

原创 puzzle 16: Line Printer 转义字符

public class LinePrinter{ public static void main(String[] args){ //Note: /u000A is Unicode representation of linefeed(LF) char c = 0x000A; System.out.println(c); }}Solut

2007-03-05 22:49:00 463

原创 Java Puzzlers笔记--puzzle 15: Hello Whirled －Unicode字符问题

/** * Generated by the IBM IDL-to-Java compiler, version 1.0 * from F:/TestRoot/apps/a1/units/include/PolicyHome.idl * Wednesday, June 17, 1998 6:55:40 oclock AM GMT +00:00 */public class Test{

2007-03-04 12:36:00 561

原创 Java Puzzlers笔记--puzzle 14: Escape Rout (")双引号的问题

public class EscapeRout{ public static void main(String[] args){ // /u0022 is the Unicode escape for double quote("); System.out.println("a/u0022.length() + /u0022b".le

2007-03-04 12:14:00 904

原创 Java Puzzlers笔记--puzzle 13: Animal Farm 优先级以及对象引用问题

public class AnimalFarm{ publi static void main(String[] args){ final String pig = "length: 10"; final Stirng dog = "length: " + pig.length(); System.out.println("Animals are equal: " + pig==dog);

2007-03-04 11:00:00 829

原创 Java Puzzlers笔记--puzzle 12: ABC String与char的区别

public class Abc{ public static void main(String[] args){ String letters = "ABC"; char[] numbers = {"1", "2", "3"}; System.out.println(letters + " easy as " + numbers ); }}Solution:

2007-03-04 10:45:00 900

原创 Java Puzzlers笔记--puzzle 11: The last laugh "" 与''的区别

public class LastLaugh{ public static void main(String[] args){ System.out.println("H" + "a"); System.out.println(H + a); }} Solution:

2007-03-04 10:30:00 517

原创 Java Puzzlers笔记--puzzle 10: Tweedledee += 问题（2）

x = x + i;but this is not:x += i;Solution: Objext x = "Buy "; Stirng i = "Effective java!"; x = x + i;//its legal.显示：But Effective java! x += i; //its illegal.因为+=操作符没有对String类型的定义。TID: The +=

2007-03-03 19:18:00 564

原创 Java Puzzlers笔记--puzzle 9: Tweedledum +=的问题

Provide declarations for the variables x and i such that this is a legal statement: x += i;but this is not: x = x + i;Solution: short x = 0; int i = 123456; x += i; // Contains a hidden cast! x =

2007-03-03 19:17:00 755

原创 Java Puzzlers笔记--puzzle 8: Dos Equis 选择操作符问题

public class DosEquis{ public static void main(String[] args){ char x = X; int i = 0; System.out.println(true ? x : 0); System.out.println(false ? i : x); }}Solution: 显示：X88 ?: 选择操作符的特别的地方

2007-03-03 19:15:00 712

原创 Java Puzzlers笔记--puzzle 7: Swap Meat ^符号问题

public class CleverSwap{ public static void main(String[] args){ int x = 1984; int y = 2001; x ^= y ^=x ^= y; System.out.println("x= " + x + "; y = " + y); }}Solution: 显示：x = 0; y = 1984; 要使用中间变

2007-03-03 19:13:00 464

原创 Java Puzzlers笔记--puzzle 6: Multicast 类型转换

public class Multicast{ public static void main(String[] args){ System.out.println((int)(char)(byte) -1); }Solution: 显示：65535 byte到char的时候出现问题，byte是由符号的，而在char里是没有符号的。}TID: the conversion from b

2007-03-03 19:12:00 536

原创 Java Puzzlers笔记--puzzle 5: The joy of Hex 十六进制计算问题

public class JosOfHex{ public void main(String[] args){ System.out.println( Long.toHexString(0x100000000 + 0xcafebabe)); }}Solution: 显示：cafebabe 由于0x100000000在int中的溢出表示为0x 0000 0001 0000 0000L 而

2007-03-03 19:09:00 615

原创 Puzzle 4: It's Elementary L与1的问题

public class Elementary{ public static void main(String[] args){ System.out.println(12345 + 5432l); }}Solution: 显示：17777 由于5432l中l是L，而不是１TID: Alwasys use a capital el(L) in long literals, neve

2007-03-03 19:03:00 403

原创 Java Puzzlers笔记--Puzzle 3: Long Division 溢出问题

public class LongDivision{ public static void main(String[] args){ final long MICROS_PER_DAY = 24*60*60*1000*1000; final long MILLIS_PER_DAY = 24*60*60*1000; System.out.printl

2007-03-01 13:55:00 647

原创 Java Puzzlers笔记--Puzzle 2: Time for a change 关于浮点型的问题

public class Change{ public static void main(String[] args){ System.out.println(2.00 - 1.10); }} Solution: 结果显示是： 0.8999999999999999999999999999 由于1.1不能用double来准确表示，而是用了一个接近的数来表示

2007-03-01 13:46:00 490

原创 Java Puzzlers笔记--Puzzle 1: Oddity奇偶问题

public static boolean isOdd(int i){ return i%2 == 1;} Solution: 以上程序只有3／4的数正确，因为当i是负数时，不管是奇数还是偶数都会返回false;java puzzlers 上的提示： test that your methods behave properly when passed negative, zero

2007-03-01 13:28:00 473

原创 java 6的认识

刚刚看完csdn上的文章介绍java虚拟机,觉得讲到java 6的一点新功能,我们必须知道的,要不我们就out了...文章是一篇Danny Coward访问;英文的原连接 http://www.artima.com/lejava/articles/dynamic_languages.html我把一些重要的地方截下来：Java SE 6 is no longer only about t

2007-02-28 21:47:00 489

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