(Computer Science) CBSE Class XII Important Questions Computer Science (2008)

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Computer Science : CBSE Class XII Important Questions Computer Science (2008)

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)