}
class Univer_Student extends Student {
boolean 婚否;
Univer_Student(int number,String name,boolean b) {
super(number,name); 婚否=b;
System.out.println(\婚否=\婚否);
} }
public class Class1 {
public static void main (String[] args) throws java.io.IOException {
int i;
Univer_Student zhang=new Univer_Student(5144,\李晓红\ i=System.in.read();
} }
答：运行结果为：I am 李晓红 my number is 5144 婚否=false
15、class Sum
{ int n; float f() {
float sum=0;
for(int i=1;i<=n;i++) sum=sum+i; return sum; }
}
class Average extends Sum {
int n; float f()
{
float c; super.n=n; c=super.f(); return c/n; }
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float g() {
float c; c=super.f(); return c/2; } }
public class Class1 {
public static void main (String[] args) throws java.io.IOException {
Average aver=new Average(); aver.n=100;
float result_1=aver.f(); float result_2=aver.g();
System.out.println(\ System.out.println(\ int i;
i=System.in.read();
} }
答：运行结果为：result_1=50.50 result_2=2525.0
16、
class Student {
float math,english,sum; float f(float k1,float k2) {
sum=k1*math+k2*english; return sum; } }
public class Average {
Student wanghong,lihong;
public static void main(String args[]) {
wanghong=new Student(); lihong=new Student(); wanghong.math=60.0f; wanghong.english=80f; lihong.math=70.0f;
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lihong.english=90.0f;
wanghong.sum=wanghong.f(2.0f,2.0f); lihong.sum=lihong.f(2.0f,2.0f);
System.out.println(\ System.out.println(\
}
}
答：运行结果为：lihong sum=320.0 wanghong sum=280.0
17、
import java.awt.*; class Chengji {
float f(float x,float y) {
return x*y; } }
class Xiangjia extends Chengji {
//重写父类的f方法
float f(float x,float y) {
return x+y; } }
public class Class1 {
Xiangjia sum;
public static void main(String args[]) {
sum=new Xiangjia();
System.out.println(\
//此处对象sum是调用自已的方法f,得到两数的和. } }
答：运行结果为：sum=10.0 18、
public class Class1 {
float a[];
public static void main(String args[])
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{
a=new float[5]; a[0]=23.9f; a[1]=34.9f; a[2]=45f; a[3]=56.98f; a[4]=100f;
System.out.println (\ System.out.println (\ System.out.println (\ System.out.println (\ System.out.println (\ } }
答：运行结果为： a[0]=23.9 a[1]=34.9 a[2]=45.0 a[3]=56.98 a[4]=100.0 19、
public class Class1 {
String tom=\ int x,y,z;
public static void main(String args[]) {
x=tom.indexOf(\
y=tom.indexOf(\ z=tom.indexOf(\ g.setColor(Color.red);
System.out.println(\ } }
答：运行结果为：2:7:13 20、
public class Class1 {
String jerry=\
public static void main(String args[]) {
s1=jerry.substring(2); s2=jerry.substring(2,5);
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g.setColor(Color.blue); System.out.println (s1); System.out.println (s2);
System.out.println (jerry.substring(jerry.indexOf(\
}
}
答：运行结果为：love Tom lov
love Tom
21、
import java.util.*; import java.awt.*; public class Class1 {
public static void main (String[] args) throws java.io.IOException {
String s1=\ String s2=\
StringTokenizer fenxi_1=new StringTokenizer(s1,\//空格和逗号做分隔符 StringTokenizer fenxi_2=new StringTokenizer(s2,\//空格和问号做分隔符 int n1=fenxi_1.countTokens(); int n2=fenxi_2.countTokens(); while(fenxi_1.hasMoreTokens()) {
String s=fenxi_1.nextToken(); System.out.print(s+“ ”); }
System.out.println();
System.out.println(\有单词:\个\ while(fenxi_2.hasMoreTokens()) {
String s=fenxi_2.nextToken(); System.out.print(s+“ ”); }
System.out.println();
System.out.println(\有单词:\个\ int i;
i=System.in.read(); } }
答：运行结果为：I am Geng.X.Y she is my girlfriend s1有单词：7个
Lowood what is that
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