CBSE Guess > Papers > Important Questions > Class XII > 2008 > Computer Science > Computer Science By Mr. Dheeraj Mehrotra
CBSE CLASS XII
Q. 31. Differentiate between read( ) & write( ) functions.
[Hint : Read & Write records]
Q. 32. Write two advantages of using include compiler directive.
[Hint : Header Files]
Q. 33. What do you understand by default constructor and copy constructor functions used in classes? How are these functions different from normal constructors?
[Hint : Member functions]
Q. 34. Differentiate between getline( ) & getc( ) functions.
[Hint : String input]
Q. 35. Illustrate the concept of Function Overloading with the help of an example.
[Hint : Multiple Methods]
Q.36. Illustrate the use of the this pointer with the help of an example.
[Hint : Classes & Objects]
Q. 37. Encapsulation is one of the major properties of OOP. How is it implemented in C++.
[Hint : OOP features]
Q. 38. Illustrate the use of “Self Referential Structures” with the help of an example.
[Hint : Data types]
Q. 39. Reusability of classes is one of the major properties of OOP. How is it implemented in C++.
[Hint : Objecters & Classes]
Q .40. Distinguish between: int*ptr=new int(5); & int * ptr= new int[5];
[Hint : Points & Array]
Q .41. Distinguish between ios::out & ios::app.
[Hint : File output/Append]
Q. 42. What is the purpose of Header file in a program.
[Hint : Include functions]
Q. 43. What do you understand by a Base Class and a Derived Class. If a base class and a derived class each include a member function with the same name and arguments, which member function will be called by the object of the derived class if the scope operator is not used.
[Hint : Polymorphism]
Q. 44. Illustrate the concept of Inheritance with the help of an example.
[Hint : OOPS]
Q. 45. What is the difference between put( ) and write( ).
[Hint : Read & Write records]
Q. 46. Will a C compiler always compile C++ code?
[Hint : NO]
Q. 47. Which is not a valid keyword: public, protected, guarded
[Hint : ‘g’]
Q. 48. What is the correct syntax for inheritance
- class aclass : public superclass
- class aclass inherit superclass
- class aclass <-superclass
[Hint : (a)]
Q. 49. What does the following do: for(;;) ;
[Hint : loop]
Q. 50. Of the numbers 12 23 9 28 which would be at the top of a properly implemented maxheap?
[Hint : Arrays]
Q. 51. What does the break; do in the following?
void afunction()
{
if(1)
{
break;
a_function();
cout<<“Err”;
}
}
[Hint : Breaks loop]
Q. 52. What are pointers, when declared, intialized to?
[Hint : Variable address]
Q. 53. What is the last index number in an array of 100 characters?
[Hint : Array option Bare]
Q. 54. Would you rather wait for quicksort, linear search, or bubble sort on a 200000 element array? (Or go to lunch...)
[Hint : Dry Run]
Q. 55. What does the following algorithm do?
set sum to zero.
set i to 1.
input n.
while i is less than or equal to n do
{
add i to sum.
increment i.
}
output sum.
What would be output if the value entered for n was 0? What would be the effect of reversing the order of the statements in the loop body on the general result produced by the algorithm?
[Hint : Dry Run]
Q. 56. If an array has a 100 elements what is the allowable range of subscripts?
[Hint : Array option base]
Q. 57. What is the difference between the expressions a4 and a[4]?
[Hint : Variable & Arrary]
Q. 58. Write a declaration for a 100 element array of floats. Include an initialisation of the first four elements to 1.0, 2.0, 3.0 and 4.0.
[Hint : Array initialialion of arrays]
Q. 59. An array day is declared as follows:
int day[] = {mon, tue, wed, thu, fri};
How many elements has the array day? If the declaration is changed to
int day[7] = {mon, tue, wed, thu, fri};
how many elements does day have?
[Hint : Array definition]
Q. 60. What would be output by the following section of C++?
int A[5] = {1 , 2, 3, 4};
int i;
for (i=0; i<5; i++)
{
A[i] = 2*A[i];
cout << A[i] << “ “;
}
[Hint : Dry Run]
Q. 61. What is wrong with the following section of program?
int A[10], i;
for (i=1; i<=10; i++)
cin >> A[i];
[Hint : Dry run]
Q. 62. Write a function heading for a function which will double the first n elements of an array. If the function was amended so that it would return false if n was larger than the size of the array how should the function heading be written? If the function was to be changed so that a new array was produced each of whose elements were double those of the input array how would the heading be written?
[Hint : Function definition]
Q. 63. What does the following do: void afunction(int *x)
{
x=new int;
*x=12;
}
int main()
{
int v=10;
afunction(&v);
cout<<v;
}
(a) Outputs 12
(b) Outputs 10
(c) Outputs the address of v
[Hint : Dry Run]
Q. 64. What do nonglobal variables default to:
- auto
- register
- static
[Hint : Variable declaeation]
Q. 65. Which header file allows file i/o with streams?
- iostream.h
- fstream.h
- fileio.h
[Hint : File stream]
Q. 66. What is the outcome of cout<<abs(-16.5);
- 16
- 17
- 16.5
[Hint : Dry run]
Q. 67. What will strcmp(“Astring”, “Astring”); return?
[Hint : String compare]
Q. 68. Evaluate !(1&&1||1&&0)
[Hint : Logical Condition]
Q. 69. What header file is needed for exit();
[Hint : Process]
Q. 60. What ANSI C++ function clears the screen?
[Hint : Clrscr]
