php mcq questions with answers


                                
Which of the following statements is correct?
                                
A.A struct never declares a default constructor.
B.All value types in C# inherently derive from ValueType, which inherits from Object.
C.A struct never declares a default destructor.
D.In C#, classes and structs are semantically same.
                              
Click To Show Ans:B

                        
                                


Which of the following statements are correct about the structure declaration given below?



struct Book
{
    private String name; 
    protected int totalpages; 
    public Single price; 
    public void Showdata()
    {
        Console.WriteLine(name + " " + totalpages + " " + price);
    } 
    Book()
    {
        name = " "; 
        totalpages = 0;
        price = 0.0f; 
    } 
} 
Book b = new Book();


    

  1. We cannot declare the access modifier of totalpages as protected.

    2. 

  2. We cannot declare the access modifier of name as private.

    3. 

  3. We  cannot define  a zero-argument constructor inside  a structure.

    4. 

  4. We cannot declare the access modifier of price as public.

    5. 

  5. We can define a Showdata() method inside a structure.

    6. 





                                
A.1, 2
B.1, 3, 5
C.2, 4
D.3, 4, 5
                              
Click To Show Ans:B

                        
                                


Which of the following are true about classes and struct?



    

  1. A class is a reference type, whereas a struct is a value type.

    2. 

  2. Objects are created using new, whereas structure variables can be created either using new or without using new.

    3. 

  3. A structure variable will always be created slower than an object.

    4. 

  4. A structure variable will die when it goes out of scope.

    5. 

  5. An object will die when it goes out of scope.

    6. 





                                
A.1, 2, 4
B.3, 5
C.2, 4
D.3, 4, 5
                              
Click To Show Ans:A

                        
                                


Which of the following statements are correct about Structures used in C#.NET?



    

  1. A Structure can be declared within a procedure.

    2. 

  2. Structs can implement an interface but they cannot inherit from another struct.

    3. 

  3. struct members cannot be declared as protected.

    4. 

  4. A Structure can be empty.

    5. 

  5. It is an error to initialize an instance field in a struct.

    6. 





                                
A.1, 2, 4
B.2, 3, 5
C.2, 4
D.1, 3
                              
Click To Show Ans:B

                        
                                


Which of the following statements are correct about an enum used inC#.NET?



    

  1. By default the first enumerator has the value equal to the number of elements present in the list.

    2. 

  2. The value of each successive enumerator is decreased by 1.

    3. 

  3. An enumerator contains white space in its name.

    4. 

  4. A variable cannot be assigned to an enum element.

    5. 

  5. Values of enum elements cannot be populated from a database.

    6. 





                                
A.1, 2
B.3, 4
C.4, 5
D.1, 4
                              
Click To Show Ans:C