It is perfectly legal to assign a subclass object to a supper class reference.
True
False
Correct Answer :
A. True
Related Questions
Any method in a supper class can be over ridden in its subclass.
True
False
Which of the following are keywords?
integer
default
Boolean
Object
When present, package must be the first no comment statement in the file.
True
False
Connection, Statement are interfaces and ResultSet is a class.
True.
False.
In RMI we invoke client method from remote server
True
False
Which of the following classes are available in the java.lang package?
Random
Stack
String Buffer
Vector
class.forName(...) creates an instance of java ODBC driver
True
False
The concept of multiple inheritance is implemented in Java by
extending two or more classes
extending one class and implementing one or more interfaces
all the above
In RMI before running the client program we must start RMI Registry.
True.
False.
A variable declared inside the for loop control can not be referenced out side the loop.
True
False
Which of the following string can be used as mode string for creating a RandomAccessFile object?
"rw"
"wr"
"0"
'w''
If a=10 and b= 15, then the statement x =(a>b)?a:b; assigns the value 15 to x.
True
False
A thread can make second thread ineligible for execution by calling the suspend (-) method on second thread.
True
False
Which of the following represent legal flow control statements?
break;
break();
continue(inner);
all of the above
It is perfectly legal to refer to any instance variable inside of a static method.
True
False
Members of a class specified as private are accessible only to the methods of the class.
True
False
We would like to make a member of a class visible in all subclasses regardless of what package they are in. Which one of the following keywords would achieve this?
private
protected
public
private protected
To delete a file, we can use an instance of class file.
True
False
Frames and applets cannot be used together in the same program.
True
False
What does the following line of code do?
TextField text=new TextField(10);
Creates text object that can hold 10 rows of text.
Creates text object that can hold 10 columns of text.
Creates the object text and initializes it with the value 10.
The code is illegal.
Which key word can protect a class in package from accessibility by the classes outside the package?
private
protected
final
don't use any keyword at all(make it default)
Servlet can have ___________
get method and post method
get method or post method
Either of the above
When we invoke repaint () for a Component, the AWT invokes the method:
draw()
update()
show()
paint()
JSP files creates ________________
html files
html files and java files
java files and class files
None of the above.
The check box group class is a subclass of the component class.
True
False
The use of protected keyword to a member in a class will restrict its visibility as follows:
Visibility only in the class and its subclasses in the same package.
Visibility only inside the same package.
Visibility in all classes in the same package and subclasses in other packages.
Visibility only in the class where it is declared.
In order to connect to a database through java program we must create _______-
Connection, Statement, ResultSet
Connection, ResultSet
Statement< ResultSet
Connection, Statement
Which of the following represent legal flow control statements?
break();
continue(inner);
return;
exit();
A method declared as static can not access non-static class members.
True
False
The import statement is always the first no comment statement in a Java program files.
True
False