C# Questions & Answers – Unsafe code & Pointers Basics

This set of C# Problems focuses on “Unsafe code & Pointers Basics”.

1. Pointer variable is used to hold the _________ of the variable.
a) Value
b) Address
c) Value and Address
d) Name of the variable

2. Which among the given operators is referred to as ‘address of’ operator?
a) *
b) ^
c) &
d) ~

                           int* ip;
                           int num = 10;
                           ip = #

3. Choose the correct statement among the given statements?
a) Use of return statement is necessary in every function
b) Return statement may not be followed by a parenthesis
c) A program may contain more than one return statement
d) Return statement may not return a value

4. What is the size of a char pointer?
a) 1 byte
b) 2 byte
c) 3 byte
d) 4 byte

             class UnsafeCode
             {
                 unsafe static void Main()
                 {
                  char ch;
                  Console.WriteLine(sizeof(char));
                  Console.ReadLine();
                 }
            }

5. After incrementing a float pointer ptr by 1 it would be incremented by __________
a) 1 byte
b) 2 bytes
c) 3 bytes
d) 4 bytes

6. Which of the following job is done by the instruction ++*p for an integer pointer p?
a) increment value contained at address p
b) increment address contained in p
c) Both increment value contained at address p and increment address contained in p
d) neither increment value contained at address p nor increment address contained in p

             class UnsafeCode
             {
                 unsafe static void Main()
                 {
                      int n = 10;
                      int* p = &n;
                      Console.WriteLine(*p);
                 }
             }

10 +  1 = 11.

7. What will be the output of the following C# code snippet?

a) 6
b) print garbage value
c) print -6
d) print address of b + a

 4 + 2 = 6

8. What will be the output of the following C# code segment?

a) The program will print 10
b) Run time error
c) Compile time error
d) Output is the address contained in p

9. Which among the following is referred as an array of pointers?
a) int *p;
b) int (*)p;
c) int p[4];
d) int*[4] p;

10. Among the given pointer which of the following cannot be incremented?
a) int
b) char
c) float
d) void

11. How many values can be returned from a function simultaneously using pointers?
a) 1
b) 2
c) 3
d) as many as user wants

12. Consider an integer pointer . *a.++*a will increment ___________ while *a++ will increment __________
a) value at a, address contained in a
b) value at a,value at a
c) address contained in a, address contained in a
d) address contained in a, value at a

13. What will be the output of the following C# code snippet?

a) program will print garbage value
b) program will print address of a
c) program will print value of a1
d) program will print address of a1

14. What will be the output of the following C# code snippet?

a) compile time error
b) garbage value is printed
c) program will print 1000
d) program will print 100

15. What will be the output of the following C# code snippet?

a) compile time error
b) garbage value
c) program prints value at address 65535
d) program prints 65535

65535