php mcq questions with answers


                                


Which of the following statements are correct about a delegate? 



    

  1. Inheritance is a prerequisite for using delegates.

    2. 

  2. Delegates are type-safe.

    3. 

  3. Delegates provide wrappers for function pointers.

    4. 

  4. The declaration of a delegate must match the signature of the method that we intend to call using it.

    5. 

  5. Functions called using delegates are always late-bound.

    6. 





                                
A.1 and 2 only
B.1, 2 and 3 only
C.2, 3 and 4 only
D.All of the above
E.None of the above
                              
Click To Show Ans:C

                        
                                


Which of the following statements are correct about delegates?



    

  1. Delegates are not type-safe.

    2. 

  2. Delegate is a user-defined type.

    3. 

  3. Only one method can be bound with one delegate object.  

    4. 

  4. Delegates can be used to implement callback notification.

    5. 

  5. Delegates permit execution of a method on a secondary thread in an asynchronous manner.

    6. 





                                
A.1 and 2 only
B.1, 2 and 3 only
C.2, 4 and 5 only
D.4 and 5 only
E.All of the above
                              
Click To Show Ans:C

                        
                                
Which of the following statements are correct about delegates?
                                
A.Delegates cannot be used to call a static method of a class.
B.Delegates cannot be used to call procedures that receive variable number of arguments.
C.If signatures of two methods are same they can be called through the same delegate object.
D.Delegates cannot be used to call an instance function. Delegates cannot be used to call an instance subroutine.
                              
Click To Show Ans:B

                        
                                


Which of the following are the correct ways to declare a delegate for calling the function func() defined in the sample class given below?



class Sample
{
    public int func(int i, Single j)
    {
        /* Add code here. */
    }
}




                                
A.delegate d(int i, Single j);
B.delegate void d(int, Single);
C.delegate int d(int i, Single j);
D.delegate void (int i, Single j);
E.delegate int sample.func(int i, Single j);
                              
Click To Show Ans:C

                        
                                
Suppose on pushing a button an object is to be notified, but it is not known until runtime which object should be notified. Which of the following programming constructs should be used to implement this idea?
                                
A.Attribute
B.Delegate
C.Namespace
D.Interface
E.Encapsulation
                              
Click To Show Ans:B