class Fish{

int weight = 1;

}

class Lake {

Fish fish;

void setFish(Fish s){

fish = s;

void foodFish( int m){

fish.weight= fish. weight+ m;

}}

public class E{

public static void main(String args[ 1){

Fish redFish = new Fish();

System. out. printin(redFish.weight);//【代码1】  

Lake lake = new Lake();

lake.setFish( redFish);lake.foodFish(120);

System.out. println(redF ish. weight);//【代码2】

System. out. println( lake.fish.weight);//【代码3】

}}

class B{

int x- 100, y - 200;public void setX( int x){=x;

public void setY( int y){this.y - y;

public int getxYSum()(

return x+y;

年

)

public class A {

public static void main( String args[J){

Bb= new B();

b.setX(- 100);

b.setY(- 200);

System.out. pr intln( " sum= "+b.getxYSum());

}}

class B(

int n;

static int sum = O;

void setN( int n){

this.n = n;

}

int getSum(){

for( int i=1;i<= n;i++)

sum=sum + i;

return sum;

}

public class A{

public static void main( String args[]){

B b1 =new B(),b2= new B();

b1 ,setN(3);

b2. setN(5);

int s1 =b1.getSum();

int s2 = b2.getSum();

System. out.println( s1 + s2);

)

}}

class A{

double f( int x, double Y){

return x +y;

int f(int x,int y){

return x* y;

public class E{

public static void main(String args[ ]){

Aa = new A();

System. out. println(a.f( 10,10));//【代码1】

System.out. println(a.f(10,10.0));//【代码2】

}}

class A{

double f(double x, double y){

return x+y;

}

class B extends A {

double f(int x, int y){

return x* y;

}

public class E{

public static void main(String args[ ]){

Bb = new B();

System.out, println(b.f(3,5)); //【代码1】

System. out. println(b.f(3.0,5.0)); /【代码2】

}}

class A{

public int getNumber( int a){

return a+1;

}}

class B extends A {

public int getNumber(int a){

return a+100;

public static void main( String args[ ]) {

A a = new A();

System.out. println(a. getNumber(10));【代码1】

a = new B();

System. out. println(a. getNumber(10));【代码1】

}}

class A{

double f( double x, double y){

return x +y;

static int g(int n){

return n * n;

class B extends A{

double f(double x, double y){

double m= super.f(x,y);return mtx * y;

static int g( int n){

int m= A.g(n);return m+n;

)

public class E{

public static void main(String args[ ]){

Bb = new B(;

8.0

System.out. printin(b.f(10.0,8.0));【代码1】

System. out. println(b.g(3));【代码2】

A a =new B();

System. out. println(a.f(10.0,8.0));【代码3】

System,out. println(a.g(3));【代码4】

class A{

int m;

int getM(){

return m;

int seeM() {

return m;

class B extends A {

int m;

int getM){

return m+ 100;

public class E{

public static void main( String args[ ){

Bb =new B();

b.m=20;

System. out. println(b. getM());【代码1】

A a = b;

a.m= -100;

System. out. println(a.getM());【代码2】

System. out. printin(b.seeM();【代码3】

}}

interface A{

double f(double x, double y);

class B implements A{

public double f(double x, double y){

return x. * Y;

int g(int a,int b){

return a+ b;

}}

public class E{

public static void main(String args[ ]){

A a = new B();

System.out. println(a. f(3,5));【代码1】

B b =(B)a;

System. out. print1n(b.g(3,5));【代码2】

}}

interface Com{

int add( int a, int b);}

abstract class A{

abstract int add( int a, int b);}

class B extends A implements Com{

public int add( int a,int b){

return a+b;

}}

public class E{

public static void main( String args[ ]){

Bb=new B();

Com com= b;

System.out. println(com. add(12,6));【代码1】

A a= b;

System.out. println(a.add( 10,5));【代码2】

interface Com {

int add( int a,int b);

oublic static int get( int n){

return n;

}}

public default int see( int n){

return n;

public default int look(int n){

return n;

}

class A implements Com{

public int add( int a,int b){

return a+b;

public int see(int n){ 

return n+1;

}}

public class E{

public static void main(Strina args[]){

A a= new A();

int n=a.add( 12,6);

int n= Com. get(12);

int t = a. see(6);

int q = a. look(6);

System. out. printf("%d:%d:%d:%d" , m, n,t,q);//【代码】

}}

class Cry {

public void cry(){

System. out. print1n("大家好");

}

public class E{

public static void main(String args[1){

Cry hello= new Cry(）{

public void cry(）{

System. out. println("大家好,祝工作顺利!");

}};

hello.ery();
}}

interface Com{

public void speak();

public class E{

public static void main(String args[]){

Com p=()->{

System. out. println("p是接口变量");

}

p.speak();

}}

import java.io.IOException;

public class E{

public static void main( String args[ ]){

try { methodA();}

catch( IOException e){

Systen, out. print("你好");

return;
}

finally {

System. out. println(" fine thanks");

}}

public static void methodA()throws IOException{

throw new IOException();

}}

class ScoreException extends Exception {

int number;

ScoreException( int number){

this. number = number;}

int getMess(){

return number;

}}

class Teacher {

public int giveScore( int score) throws ScoreException {

if( score> 100  || score< 0)

throw new ScoreException(score);return score;

}}

public class E{

public static void main( String args[] ){

Teacher t = new Teacher();

int m=0,n=0;try{

m=t.giveScore(100);

m=t.giveScore( 101);

}

catch(ScoreException e){

n = e. getMess();

}

System.out.printf("%d:% d", m, n);

}}

class RedCowFarn{

static class RedCow {

void speak()i

System. out. println("我是红牛");

}

class BlackCowEarm {

public static void main(String args[ ])(

RedCowFarm. RedCow red=

new RedCowFarm.RedCow();

Red.speak（）;

}}

public class E{

public static void main( String[]args){

String str = new String("苹果");

modify(str);

System. out. println(str);  【代码】

}

public static void modify(String s){

s =s+"好吃";

}}

import java. uti1.*;

class GetToken{

String s[];

public String getToken( int index,String str){

StringTokenizer fexi = new StringTokenizer(str)；

Int number fenxi.counttokens();

s=new String[ number +1]；

int k =1;

while(fenxi. hasMoreTokens()){

String temp = fenxi. nextToken();

s[k]=temp;

k++;

}

if( index< =number)

return s[ index];

else

return null;

}}

class E(

public static void main(String args[ ]){

String str = "We Love This Game";

GetToken token = new GetToken();

String s1=token. getToken(2,str),

52token. getToken( 4,str);

System.out. printin(sl+ ":"+s2);//【代码】

}}

public classE{

public static void main( String args[ 1) {

byted[ ] = "abc我们喜欢篮球". getBytes();

Systen.out. printin(d.length);【代码1】

String s = new String(d,0,7);System. out, print1n(s);【代码2】

}}

class MyString {

public String getString( String s){

StringBuffer str = new StringBuffer();for(int i=0;i< s.length();i++){

if(i%2==0){

char c = s.charAt(i);str.append(c);

}

return new String(str);

}

public class E{

public static void main(String args[ ]){

String s="1234567890";

MyString ms=new Mystring();

System. out. println(ms.getString(s));【代码】

}}