11.Given the following class definition:
class A{
protected int i;
A(int i){
this.i=i;
}
}
which of the following would be a valid inner class for this class?
Select all valid answers:
A. class B{
}
B. class B extends A{
}
C. class B extends A{
B(){System.out.println(“i=”+i);}
}
D. class B{
class A{}
}
E. class A{}
12. Which modifier should be applied to a method for the lock of object this to be obtained prior to excution any of the method body?
A. synchronized
B. abstract
C. final
D. static
E. public
13. The following code is entire contents of a file called Example.java,causes precisely one error during compilation:
1) class SubClass extends BaseClass{
2) }
3) class BaseClass(){
4) String str;
5) public BaseClass(){
6) System.out.println(“ok”);}
7) public BaseClass(String s){
8) str=s;}}
9) public class Example{
10) public void method(){
11) SubClass s=new SubClass(“hello”);
12) BaseClass b=new BaseClass(“world”);
13) }
14) }
Which line would be cause the error?
A. 9 B. 10 C. 11 D.12
14. Which statement is correctly declare a variable a which is suitable for refering to an array of 50 string empty object?
A. String [] a
B. String a[]
C. char a[][]
D. String a[50]
F. Object a[50]
15. Give the following java source fragement:
//point x
public class Interesting{
//do something
}
Which statement is correctly Java syntax at point x?
A. import java.awt.*;
B.package mypackage
C. static int PI=3.14
D. public class MyClass{//do other thing…}
E. class MyClass{//do something…}
16. Give this class outline:
class Example{
private int x;
//rest of class body…
}
Assuming that x invoked by the code java Example, which statement can made x be directly accessible in main() method of Example.java?
A. Change private int x to public int x
B. change private int x to static int x
C. Change private int x to protected int x
D. change private int x to final int x
17. the piece of preliminary analsis work describes a class that will be used frequently in many unrelated parts of a project
“The polygon object is a drawable, A polygon has vertex information stored in a vector, a color, length and width.”
Which Data type would be used?
A. Vector
B. int
C. String
D. Color
E. Date
18. A class design requires that a member variable should be accessible only by same package, which modifer word should be used?
A. protected
B. public
C. no modifer
D. private
19.Which declares for native method in a java class corrected?
A. public native void method(){}
B. public native void method();
C. public native method();
D. public void method(){native;}
E. public void native method();
20. Which modifer should be applied to a declaration of a class member variable for the value of variable to remain constant after the creation of the object?
