编程思想课后习题答案

1、Java编程思想（第四版）习题答案第二章练习1：public class PrimitiveTest static int i;static char c;public static void main(String args) System.out.println("int = " + i);System.out.println("char = " + c);练习2：public class HelloWorld public static void main(String args) System.out.println("Hello Wo

2、rld!");练习3：public class ATNTest public static void main(String args) class ATypeName int i;double d;boolean b;void show() System.out.println(i);System.out.println(d);System.out.println(b);ATypeName a = new ATypeName();a.i = 3;a.d = 2.71828;a.b = false;a.show();练习4：public class DataOnlyTest publ

3、ic static void main(String args) class DataOnly int i;double d;boolean b;void show() System.out.println(i);System.out.println(d);System.out.println(b);DataOnly data = new DataOnly();data.i = 3;data.d = 2.71828;data.b = false;data.show();练习5：public class DOTest2 public static void main(String args) c

4、lass DataOnly int i;double d;boolean b;void show() System.out.println(i);System.out.println(d);System.out.println(b);DataOnly data = new DataOnly();data.i = 234;data.d = 2.1234545;data.b = true;data.show();练习6：public class StorageTest public static void main(String args) class StoreStuff int storage

5、(String s) return s.length() * 2;StoreStuff x = new StoreStuff();System.out.println(x.storage("hi");练习7：class StaticTest static int i = 47;class Incrementable static void increment() StaticTest.i+; public class ITest public static void main(String args) System.out.println("StaticTest.

6、i= " + StaticTest.i);StaticTest st1 = new StaticTest();StaticTest st2 = new StaticTest();System.out.println("st1.i= " + st1.i);System.out.println("st2.i= " + st2.i);Incrementable sf = new Incrementable();sf.increment();System.out.println("After sf.increment() called: &q

7、uot;);System.out.println("st1.i = " + st1.i);System.out.println("st2.i = " + st2.i);Incrementable.increment();System.out.println("After Incrementable.increment called: ");System.out.println("st1.i = " + st1.i);System.out.println("st2.i = " + st2.i);练

8、习8：class StaticTest static int i = 47;class Incrementable static void increment() StaticTest.i+; public class OneStaticTest public static void main(String args) System.out.println("StaticTest.i= " + StaticTest.i);StaticTest st1 = new StaticTest();StaticTest st2 = new StaticTest();System.ou

9、t.println("st1.i= " + st1.i);System.out.println("st2.i= " + st2.i);Incrementable.increment();System.out.println("After Incrementable.increment() called: ");System.out.println("st1.i = " + st1.i);System.out.println("st2.i = " + st2.i);Incrementable.in

10、crement();System.out.println("After Incrementable.increment called: ");System.out.println("st1.i = " + st1.i);System.out.println("st2.i = " + st2.i);st1.i = 3;System.out.println("After st1.i = 3, ");System.out.println("st1.i = " + st1.i);System.out.p

11、rintln("st2.i = " + st2.i);System.out.println("Create another StaticTest, st3.");StaticTest st3 = new StaticTest();System.out.println("st3.i = " + st3.i);练习9：public class AutoboxTest public static void main(String args) boolean b = false;char c = 'x'byte t = 8;s

12、hort s = 16;int i = 32;long l = 64;float f = 0.32f;double d = 0.64;Boolean B = b;System.out.println("boolean b = " + b); System.out.println("Boolean B = " + B); Character C = c;System.out.println("char c = " + c);System.out.println("Character C = " + C);Byte T

13、 = t;System.out.println("byte t = " + t);System.out.println("Byte T = " + T);Short S = s;System.out.println("short s = " + s);System.out.println("Short S = " + S);Integer I = i;System.out.println("int i = " + i);System.out.println("Integer I = &

14、quot; + I);Long L = l;System.out.println("long l = " + l);tln("Long L = " + L);Float F = f;System.out.println("float f = " + f);System.out.println("Float F = " + F);Double D = d;System.out.println("double d = " + d);System.out.println("Double D

15、= " + D);练习10：public class CommandArgTest public static void main(String args) System.out.println("args0 = " + args0);System.out.println("args1 = " + args1);System.out.println("args2 = " + args2);练习11：public class Rainbow public static void main(String args) AllThe

16、ColorsOfTheRainbow atc = new AllTheColorsOfTheRainbow();System.out.println("atc.anIntegerRepresentingColors = " + atc.anIntegerRepresentingColors);atc.changeColor(7);atc.changeTheHueOfTheColor(77);System.out.println("After color change, atc.anIntegerRepresentingColors = " + atc.a

17、nIntegerRepresentingColors);System.out.println("atc.hue = " + atc.hue);class AllTheColorsOfTheRainbow int anIntegerRepresentingColors = 0;int hue = 0;void changeTheHueOfTheColor(int newHue) hue = newHue;int changeColor(int newColor) return anIntegerRepresentingColors = newColor;练习12：public

18、 class DocTest /* Entry poing to class & application.* param args array of string arguments* throws exceptions No exceptions thrown*/public static void main(String args) System.out.println("Hello, it's: ");System.out.println(new Date();练习13-1：public class Documentation1 /* A field

19、comment */public int i;/* A method comment */public void f() 2：public class Documentation2 Date d = new Date();void showDate() System.out.println("Date = " + d);3：public class Documentation3 public static void main(String args) Date d = new Date();System.out.println("d = " + d);练

20、习14：public class Documentation4 public int i = 2;private int j = 3;public static void main(String args) Date d = new Date();System.out.println("d = " + d);练习15：public class HelloDocTest public static void main(String args) ln("Hello World!");练习16：class Tree int height;Tree() Syst

21、em.out.println("Planting a seedling");height = 0;Tree(int initialHeight) height = initialHeight;System.out.println("Creating new tree that is " + height + " feet tall");void info() System.out.println("Tree is " + height + " feet tall");void info(Stri

22、ng s) System.out.println(s + ": Tree is " + height + " feet tall");public class Overloading public static void main(String args) for(int i = 0; i < 5; i+) Tree t = new Tree(i);();("overloading method");/ Overloaded constructor:new Tree();第三章练习1：public cla

23、ss PrintTest public static void main(String args) print("Hello, from short form.");P.rintln("Hello from greggordon form.");System.out.println("Hello from long form.");练习2：class Tube float level;public class Assign public static void main(String args) Tube t1 = new Tube(

24、);Tube t2 = new Tube();t1.level = 0.9f;t2.level = 0.47f;P.rintln("1: t1.level: " + t1.level + ", t2.level: " + t2.level);t1 = t2;P.rintln("2: t1.level: " + t1.level + ", t2.level: " + t2.level);t1.level = 0.27f; P.rintln("3: t1.level: " + t1.level +

25、", t2.level: " + t2.level);练习3：class Box float a;public class PassObject2 static void f(Box y) y.a = 2.71828f;public static void main(String args) Box x = new Box();x.a = 3.1416f;print("1: x.a = " + x.a);f(x);print("2: x.a = " + x.a);练习4：class VelocityCalculator static

26、float velocity (float d, float t) if(t = 0) return 0f;else return d/t; public class VelocityTester public static void main(String args) float d = 565.3f;float t = 3.6f;System.out.println("Distance: " + d);System.out.println("Time: " + t);float v = VelocityCalculator.velocity(d, t

27、);System.out.println("Velocity: " + v);练习5：class Dog String name;String says;void setName(String n) name = n;void setSays(String s) says = s;void showName() P.rintln(name);void speak() P.rintln(says);public class DogTest public static void main(String args) Dog spot = new Dog();spot.setNam

28、e("Spot");spot.setSays("Ruff!");Dog scruffy = new Dog();scruffy.setName("Scruffy");scruffy.setSays("Wurf!");spot.showName();spot.speak();scruffy.showName(); scruffy.speak();练习6：class Dog String name;String says;void setName(String n) name = n;void setSays(String s) says = s;void showName() P.rintln(name);void speak() P.rintln(says);public class DogCompare public static void main(String args) Dog spot = new Dog();spot.se