JAVA题库:格林模拟试题三（下）(3)

question 38)

which of the following statements are true?

1) code must be written if the programmer wants a frame to close on selecting the system close menu
2) the default layout for a frame is the borderlayout manager
3) the layout manager for a frame cannot be changed once it has been assigned
4) the gridbaglayout manager makes extensive use of the the gridbagconstraints class.

question 39)

given the following class definition

public class droitwich{
        class one{
                private class two{
                        public void main(){
                        system.out.println("two");
                        }
                }
        }
}

which of the following statements are true

1) the code will not compile because the classes are nested to more than one level
2) the code will not compile because class two is marked as private
3) the code will compile and output the string two at runtime
4) the code will compile without error

question 40)

given the following code

class base{
static int oak=99;
}

public class doverdale extends base{
public static void main(string argv[]){
        doverdale d = new doverdale();
        d.amethod();
        }
        public void amethod(){
        //here
        }       
}

which of the following if placed after the comment //here, will compile and modify the value of the variable oak?

1) super.oak=1;
2) oak=33;
3) base.oak=22;
4) oak=50.1;