JAVA编程思想课后习题答案-.pdf
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 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 public 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)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=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)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.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:);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.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);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.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=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=+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);System.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 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,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 anIntegerRepresentingColors=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 Documentation1 /*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：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)System.out.println(Hello World!);练习 16：class Tree int height;Tree()System.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(String 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);t.info();t.info(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 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.level:+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);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);float v=V elocityCalculator.velocity(d,t);System.out.println(V elocity:+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.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 DogCompare public static void main(String args)Dog 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();Dog butch=new Dog();butch.setName(Butch);butch.setSays(Hello!);butch.showName();butch.speak();P.rintln(Comparison:);P.rintln(spot=butch:+(spot=butch);P.rintln(spot.equals(butch):+spot.equals(butch);P.rintln(butch.equals(spot):+butch.equals(spot);P.rintln(Now assign:spot=butch);spot=butch;P.rintln(Compare again:);P.rintln(spot=butch:+(spot=butch);P.rintln(spot.equals(butch):+spot.equals(butch);P.rintln(butch.equals(spot):+butch.equals(spot);P.rintln(Spot:);spot.showName();spot.speak();P.rintln(Butch:);butch.showName();butch.speak();练习 7：
