10. interface Foo {}
11. class Alpha implements Foo {}
12. class Beta extends Alpha {}
13. class Delta extends Beta {
14. public static void main( String[] args) {
15. Beta x = new Beta();
16. // insert code here
17. }
18. }
Which code, inserted at line 16, will cause a java.lang.ClassCastException?()
A. Alpha a = x;
B. Foo f= (Delta)x;
C. Foo f= (Alpha)x;
D. Beta b = (Beta)(Alpha)x;
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31. // some code here
32. try {
33. // some code here
34. } catch (SomeException se) {
35. // some code here
36. } finally {
37. // some code here
38. }
Under which three circumstances will the code on line 37 be executed?()
A. The instance gets garbage collected.
B. The code on line 33 throws an exception.
C. The code on line 35 throws an exception.
D. The code on line 31 throws an exception.
E. The code on line 33 executes successfully.
public class Test {
public static void main(String [] args) {
int x =5;
boolean b1 = true;
boolean b2 = false;
if((x==4) && !b2)
System.out.print(”l “);
System.out.print(”2 “);
if ((b2 = true) && b1)
System.out.print(”3 “);
}
}
What is the result?()
A. 2
B. 3
C. 1 2
D. 2 3
E. 1 2 3
F. Compilation fails.
G. Au exceptional is thrown at runtime.
10. public class Bar {
11.static void foo(int...x) {
12. // insert code here
13. }
14. }
Which two code fragments, inserted independently at line 12, will allow the class to compile?()
A. foreach(x) System.out.println(z);
B. for(int z : x) System.out.println(z);
C. while( x.hasNext()) System.out.println( x.next());
D. for( int i=0; i< x.length; i++ ) System.out.println(x[i]);
11. public interface Status {
12. /* insert code here */ int MY_VALUE = 10;
13. }
Which three are valid on line 12?()
A. final
B. static
C. native
D. public
E. private
F. abstract
G. protected
Given the following code:
1) class Parent {
2) private String name;
3) public Parent(){}
4) }
5) public class Child extends Parent {
6) private String department;
7) public Child() {}
8) public String getValue(){ return name; }
9) public static void main(String arg[]) {
10) Parent p = new Parent();
11) }
12) }
Which line will cause error?()
A. line 3
B. line 6
C. line 7
D. line 8
E. line 10
A. FlowLayout
B. CardLayout
C. North and South of BorderLayout
D. East and West of BorderLayout
E. GridLayout
class Parent {
String one, two;
public Parent(String a, String b){
one = a;
two = b; }
public void print(){ System.out.println(one); } }
public class Child extends Parent {
public Child(String a, String b){
super(a,b);
}
public void print(){
System.out.println(one + " to " + two);
}
public static void main(String arg[]){
Parent p = new Parent("south", "north");
Parent t = new Child("east", "west");
p.print();
t.print();
}
}
Which of the following is correct?()
A. Cause error during compilation.
B. south east
C. south to north east to west
D. south to north east
E. south east to west
public class Parent {
int change() {…}
}
class Child extends Parent {
}
Which methods can be added into class Child?()
A. public int change(){}
B. int chang(int i){}
C. private int change(){}
D. abstract int chang(){}
A. long l = 4990;
B. int i = 4L;
C. float f = 1.1;
D. double d = 34.4;
E. double t = 0.9F;
String s= "hello";
String t = "hello";
char c[] = {’h’,’e’,’l’,’l’,’o’} ;
Which return true?()
A. s.equals(t);
B. t.equals(c);
C. s==t;
D. t.equals(new String("hello"));
E. t==c;
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