调试一程序
import java.util.*;
interface fly{
void start();
void land();}

class Airplane implements fly{
int meal;
int lunch;

public void start(int a){
meal=a;

}

public void land(int b)
{lunch=b;}

int getstart(){return meal;}
int getland(){return lunch;}
}


public class Ok{

public static void main(String[] args){
Airplane c=new Airplane();
c.start(10);
c.land(20);
System.out.println( "this is value: "+c.getstart());
System.out.println( "this is value: "+c.getland());}

}


请各位高手看看这个错误到底是错在哪里


[解决办法]
import java.util.*;

interface fly {
void start(int a);

void land(int a);
}

class Airplane implements fly {
int meal;

int lunch;

public void start(int a) {
meal = a;

}

public void land(int b) {
lunch = b;
}

int getstart() {
return meal;
}

int getland() {
return lunch;
}
}

public class Example {

public static void main(String[] args) {
Airplane c = new Airplane();
c.start(10);
c.land(20);
System.out.println( "this is value: " + c.getstart());
System.out.println( "this is value: " + c.getland());
}

}
你接口中的方法必须也是带参数的
[解决办法]
1楼说的对．