JAVA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 World!);练习 3： public class A

2、TNTest 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 public static void main(String

3、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) class DataOnly int i; d

4、ouble 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(String s) re

5、turn 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.i= + StaticTest.i);StaticTest

6、 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: );System.out.println(st1.i = + st1.i);System.out.println(st2.i = + st2

7、.i);Incrementable.increment();System.out.println(After Incrementable.increment called: );System.out.println(st1.i = + st1.i);System.out.println(st2.i = + st2.i);练习 8： class StaticTest static int i = 47;class Incrementable static void increment() StaticTest.i+; public class OneStaticTest public stati

8、c void main(String args) System.out.println(StaticTest.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.increment();System.out.println(After Incrementable.increment() called: );S

9、ystem.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);st1.i = 3;System.out.println(After st1.i = 3, ); System.out.println(st1.

10、i = + st1.i); System.out.println(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;short s = 16;int i

11、 = 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 = t;System.out.println(byte t = + t); System.out.println(Byte T =

12、+ 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 = + I); Long L = l;System.out.println(long l = + l); System.out.println(Long L = + L); Float F = f;System.out.println(float f = + f); Sy

13、stem.out.println(Float F = + F); Double D = d;System.out.println(double d = + d); System.out.println(Double D = + 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

14、11：public class Rainbow public static void main(String args) AllTheColorsOfTheRainbow atc = new AllTheColorsOfTheRainbow(); System.out.println(atc.anIntegerRepresentingColors = + atc.anIntegerRepresentingColors); atc.changeColor(7);atc.changeTheHueOfTheColor(77);System.out.println(After color change

15、, atc.anIntegerRepresentingColors = atc.anIntegerRepresentingColors);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 anIntegerRepresentingC

16、olors = newColor;练习 12：public 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, its: ); System.out.println(new Date();练习 13-1： public class Documentati

17、on1 /* A field 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);练习 14：pub

18、lic 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) System.out.println(Hello World!);练习 16： class Tree int height; Tree() System.out.prin

19、tln(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(String s) System.out.println(s + : Tree is + height + feet tall);public clas

20、s 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 class PrintTest public static void main(String args) print(Hello, from short form.); P.rintln(Hello from greggordon

21、 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();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.lev

22、el: + t1.level + , t2.level: + t2.level); t1.level = 0.27f;P.rintln(3: t1.level: + t1.level + , 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

23、);print(2: x.a = + x.a);练习 4： class VelocityCalculator static 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);floa

24、t v = VelocityCalculator.velocity(d, t); 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

25、spot = new Dog(); spot.setName(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 D