BS(CS) BS(SE) CS201 - Introduction to Programming MCS MIT Virtual University of Pakistan

CS201 – Introduction to Programming Final Term Solved Papers

CS201 - Introduction to Programming Final Term Solved Papers

CS201 – Introduction to Programming Final Term Solved Papers

Identify each of the following as system software and application software.

LINUX, DISK CLEANUP, WORD PROCESSOR, WINDOWS, STUDENT INFORMATION

Answer:

System software: Linux, Disk cleanup, windows.

Application software: Word Processor, Student information

Write a program which defines three variables of type double which store three different values including decimal points, using set precision manipulators to print all these values with different numbers of digits after the decimal number.

Answer:

#include

#include

int main ()

{

double x1 = 12345624.72345

double x2 = 987654.12345

double x3 = 1985.23456

cout << setprecision (3) << x1<< endl;

cout << setprecision (4) << x2 << endl;

cout << setprecision (5) << x3<< endl;

return 0;

}

Define static variable also explain life time of static variable?

Answer:

Static variable means maintaining the state of a variable. It exists and lives around even when we are outside the function. It is created and initialized only once during the lifetime of the program and therefore it will be destroyed or taken out of memory only once during the lifetime of the program.

What is limitation of the friendship between classes?

Answer:

Friendship relation between classes is a one way relation that is if one class declare friend another class then the another class is the friend of first class but not the first class if the friend of another class.

What is the source and destination of cin?(2)

Answer:

For cin, the source is normally keyboard and the destination can be an ordinary variable i.e. native-data type variable

Write the general syntax of allocation memory dynamically to an array using new operator? (2)

Answer: Page 332

Following is the syntax:

new data_type [number_of_locations];

What is different between pointer and variable?

Answer:-

Normal variable contains the value of variable either int or float whereas pointer variable contains the address of another variable

What is difference between Unary and binary operators and how they can be overloaded?

Answer:-

Unary operator takes one argument, a ++ is an example of unary operator

Binary take two operators, +,-,* are example of binary operators

Overloaded binary operator may return any type. Here is general syntax of overloading

Return-type operator symbol (parameters);

Operator is keyword

How many types of templates?

Answer:-

There are two different types of templates in C++ language i.e.’ function templates and class templates.

Identify the errors in the following member operator function and also correct them.

math * operator(math m);

math * operator (math m)

{

math temp;

temp.number= number * number;.2

return number;

Answer:-

The errors are in the arguments of the member operation function and also in the body of operator member function. Correct function should be

math *operator(math *m);

math *operator (math *m)

{

math temp;

temp = m;

temp.number= number * number;

return temp.number;

Define buffer? Explain its usage? 5 MARKS

Answer:

A program that writes the output data to the disc, it will be nice to collect the output data (numbers) and write it on the disc in one write operation instead of writing the numbers one by one. The area where we gather the numbers is known as buffer.

Why binary search algorithm is efficient than linear search algorithm?

Answer: (page118)

Binary search algorithm is more efficient than liner algorithm because the arrays are sorted in ascending or descending order and we use “divide and conquer” technique. In binary search each iteration reduces the search by the factor of two but in the linear we have the same number of searches as we have the number of elements. E.g. if we have array of 1000 elements the linear search will take 1000 iterations however binary search will take max 10.

Post increment and pre increment k syntax btana thay(2 marks)

Answer:

Classname operator ++(); —- pre increment

Classname operator ++(int) —- post increment

What is language translator?(2 marks)

Answer: Page 12

So we need a translator which translates the code of our program into machine language. There are two kinds of translators which are known as Interpreter and Compilers. These translators translate our program which is written in C-Language into Machine language

Question No.6:

Write something about testing in designing program? 3 MARKS

Answer:-

Testing. The programmer should design a test plan and use it to test the program. It is a good idea, when possible, to have someone else test the program.

Read the given below code and explain what task is being performed by this function 5 MARKS

Matrix :: Matrix ( int row , int col )

{

numRows = row ;

numCols = col ;

elements = new ( double * ) [ numRows ] ;

for ( int i = 0 ; i < numRows ; i ++ )

{

elements [ i ] = new double [ numCols ] ;

for ( int j = 0 ; j < numCols ; j ++ )

elements [ i ] [ j ] = 0.0 ;

}

}

Hint : This function belong to a matrix class, having

Number of Rows = numRows

Number of Columns = numCols

Which one (copy constructor or assignment operator) will be

called in each of the following code segment?

1) Matrix m1 (m2);

2) Matrix m1, m2;

m1 = m2;

3) Matrix m1 = m2;

Answer:-

In this code the matrix function is defined, it get the number of rows from the user and create the row of matrix and then get the columns from the user and create the columns. The New is showing for creating more array space for the data which user enters. The elements [i][j] will print the data in matrix

How many arguments a Unary Operator take? Can we make a binary operator as unary operator?

Answer:-

Unary operator takes only one arguments like i++ or i– (Post increment or post decrement operators for integers) or ++i,–i (Pre-increment or pre-decrement operators for integers) ,we cannot make Unary operator as binary or binary as Unary operator.

Which arithmetic operators cannot have a floating point operand?

Answer:-

Modulus operator: This operator can only be used with integer operands ONLY

What are manipulators? Give one example.

Answer:-

The manipulators are like something that can be inserted into stream, effecting a change in the behavior. For example, if we have a floating point number, say pi (л), and have written it as float pi = 3.1415926 ; Now there is need of printing the value of pi up to two decimal places i.e. 3.14. This is a formatting functionality. For this, we have a manipulator that tells about width and number of decimal points of a number being printed.

OR

Answer: Manipulators are operators used in C++ for formatting output. The data is manipulated by the programmer’s choice of displayed. Endl manipulator: This manipulator has the same functionality as the „\n newline character.

Which one (copy constructor or assignment operator) will be called in each of the following code segment?

1) Matrix m1 (m2);

2) Matrix m1, m2;

m1 = m2;

3) Matrix m1 = m2;

Answer:-

1) Matrix m1 (m2); copy constructor

2) Matrix m1, m2;

m1 = m2; assignment operator

3) Matrix m1 = m2; assignment operator

What will be the output of following function if we call this function by passing int 5?

template <class T>

T reciprocal(T x)

{

return (1/x);

}

Answer:-

0

The output will zero as 1/5 and its .05 but conversion to int make it zero۔

Above is prototype of template class so assume passing an int and returning an int۔

Question No: 34 ( Marks: 5 )

Write a program which defines three variables of type double which store three different values including decimal points, using set precision manipulators to print all these values with different number of digits after the decimal number.

Answer:-

#include <iostream>

#include <iomanip>

int main ()

{

double x1 = 12345624.72345

double x2 = 987654.12345

double x3 = 1985.23456

cout << setprecision (3) << x1<< endl;

cout << setprecision (4) << x2 << endl;

cout << setprecision (5) << x3<< endl;

return 0;

}

Write a declaration statement for an array of 10 elements of type float. Include an initialization statement of the first four elements to 1.0, 2.0, 3.0 and 4.0.

Answer:

float floatArry[10] = {1.0,2.0,3.0,4.0};

Question No: 2 ( Marks: 2 )

Write the general syntax for the declaration of pre-increment and postincrement

member operator function.

Answer:

Classname operator ++(); —- pre increment

Classname operator ++(int) —- post increment

Question No: 3 ( Marks: 2 )

Give the general syntax of class template.

Answer:

template

class myclass { —} ;

Question No: 4 ( Marks: 2 )

What is a truth Table?

Answer:

There are some areas where the decision structures become very complicated. Sometimes, we find it difficult to evaluate a complicated logical expression. Sometimes the logic becomes extremely complicated so that even writing it as a simple syntax statement in any language. It becomes complicated to determine what will be evaluated in what way. We know the concept of truth table. The truth tables are very important. These are still a tool available for analyzing logical expressions. We will read logic design in future, which is actually to do with chips and gates. How we put these things together.

What will be the output of following code, if user input a number 123?

int input ;

cin >> oct >> input;

cout << hex << input ;

Answer:

53

Rational: it will take 123 as octal and print it in hex form which is 53.

What is principle of friendship in the context of functions and classes?

Answer:

Class can declare a friend function and someone from outside the class cannot declare itself friend of a class. A friend function can access the private variables of class just like a member function.

How many arguments a Unary Operator take? Can we make a binary operator as unary operator?

Answer:

Unary operator takes only one argument like i++ or i— (Post increment or post decrement operators for integers) or ++i,–i (Pre increment or pre decrement operators for integers) ,we can not make Unary operator as binary or binary as Unary operator.

Which arithmetic operators cannot have a floating point operand?

Answer:

Modulus operator: This operator can only be used with integer operands ONLY

What are manipulators? Give one example.

Answer:

The manipulators are like something that can be inserted into stream, effecting a change in the behavior. For example, if we have a floating point number, say pi (л), and have written it as float pi = 3.1415926 ;

Now there is need of printing the value of pi up to two decimal places i.e. 3.14. This is a formatting functionality. For this, we have a manipulator that tells about width and number of decimal points of a number being printed.

Write down piece of code that will declare a matrix of 3×3. And initialize all its locations with 0;

Answer:

int matrix [3] [3] ;

include<iostream.h>

main () {

int matrix [3][3];

int inivalue = 0;

for (int a=0;a<3;a++)

{ for (int b = 0;b<3;b++)

{ matrix[a][b]= inivalue;

cout<<matrix[a][b]<<endl;}}

What is the difference between switch statement and if statement.

Answer:

The “If” statement is used to select among two alternatives. It uses a Boolean expression to decide which alternative should be executed.

The switch statement is used to select among multiple alternatives. It uses an int expression to determine which alternative should be executed.

How can we initialize data members of contained object at construction time?

Answer:

Initializer list is used to initialize the contained objects at the construction time.

Can we overload new and delete operators?

Answer:

Yes, it is possible to overload new and delete operators to customize memory management. These operators can be overloaded in global (non-member) scope and in class scope as member operators.

Suppose there is a template function ‘func’ having argument of type U and return type T. What will be the C++ syntax to call this function, passing a variable ‘x’ of type double and returning an int type?

Answer:

template <class T, class U>

T func (T a, U b) {

return (a<b?a:b);

}

calling

int i;

double x;

x = func<int,double> (j,l);


Question No: 15 ( Marks: 2 )

Which variable will be used in inner code block if we have the same names of variable at outer code block and inner code block?

Answer:

Simply: variable of the inner code is use in the inner code block.

What is the benefit of reference and where can we use it?

Answer:

In references we give the memory address of the object, due to references we pass values without making the copy. Hence, when we have many values & we want efficiency we use references to avoid copy.

Write the C++ code for the declaration of overloaded stream insertion and stream extraction operator for the object d of type Date.

Answer:

Date operator >> (date & d1){

cout<<d1.day<<”-”<<d1.month<<”-”<<d1.year;

}

Question No: 18 ( Marks: 2 )

What is difference between endl and \n?

Answer:

Endl is manipulator and it inserts new line character and flushes the stream.

\n is control character which is used to insert line break.

Question No: 19 ( Marks: 2 )

What does code optimization mean?

Answer:

It is process by which we make our code such a way that it improves the speed of program. By use of optimization we refine program codes in such a way that it run faster and consume less memory. We do it in such a way that output quality is not compromised.

How is the following cout statement interpreted by compiler?

cout << a << b << c ;

Answer:

It will give a compiler error because a,b,c are not declared.

Suppose an object of class A is declared as data member of class B.

(i) The constructor of which class will be called first?

Answer: A

(ii) The destructor of which class will be called first?

Answer: B

What will be the output of following functions if we call these functions three times?

1) void func1(){

int x = 0;

x++;

cout << x << endl;

}

Answer:

11

1

2) void func2(){

static int x = 0 ;

x++;

cout << x << endl ;

}

Answer:

1

23

If is not available in the system then what does calloc/malloc and new operator return?

Answer:

calloc/malloc and new operator return returns a null pointer to indicate that no memory is available.

What is the keyword ‘this’ and what are the uses of ‘this’ pointer?

Answer:

‘this’ is use to refer the current class member without using the name of the class.

Which one (copy constructor or assignment operator) will be called in each of the following code segment?

1) Matrix m1 (m2);

2) Matrix m1, m2;

m1 = m2;

3) Matrix m1 = m2;

Answer:

1) Matrix m1 (m2); copy constructor

2) Matrix m1, m2;

m1 = m2; assignment operator

3) Matrix m1 = m2; assignment operator

Question No: 26 ( Marks: 3 )

What will be the output of following function if we call this function by passing int 5?

template T reciprocal(T x) {return (1/x); }

Answer:

0

The output will zero as 1/5 and its .05 but conversion to int make it

zero

Above is prototype of template class so assume passing an int and

returning an int

Question No: 27 ( Marks: 3 )

Identify the errors in the following member operator function and also correct them.

math * operator(math m);

math * operator (math m)

{

math temp;

temp.number= number * number;

return number;

}

Answer:

The errors are in the arguments of the member operation function and also in the body of operator member function. Correct function should be

math *operator (math *m)

{

math temp;

temp = m;

temp.number= number * number;

return temp.number;

}

What are the limitations of the friendship relation between classes?

Answer:

Friendship relation between classes is a one way relation that is if one class declare friend another class then the another class is the friend of first class but not the first class if the friend of another class.

Define static variable. Also explain life time of static variable?

Answer:

When you declare a static variable (native data type or object) inside a function, it is created and initialized only once during the lifetime of the program.

What steps we must follow to design good program?

Answer 1:

  • Hence to design a program properly, we must:
  • Analyze a problem statement, typically expressed as a word problem.
  • Express its essence, abstractly and with examples.
  • Formulate statements and comments in a precise language.
  • Evaluate and revise the activities in light of checks and tests and
  • Pay attention to detail.

Answer 2:

Details: we must check very details of any program. It is very important aspect of any program. We must pay complete attention to calculation.

We must give attention to logic and its flow should be smooth.

Reusable: We must write program in such a way that we can reuse them in other program. Like we define function in such a way that in future if we need any similar kind of function is requires in that case we can easily modify or reuse it.

Comments: we write the details of important steps in the form of comments. We should use comments in such a way if any body else wanted to reuse or debug or codes he can easily understand it.

Code readability: We should use Tab and spaces so codes are easily readable.

User interface: we make interface user friendly. Use polite prompts for user while take input.

Write a program which defines five variables which store the salaries of five employees, using setw and setfill manipulators to display all these salaries in a column.

Note: Display all data with in a particular width and the empty space should be filled with character x

Output should be displayed as given below:

xxxxxx1000

xxxxxx1500

xxxxx20000

xxxxx30000

xxxxx60000

Answer:

#include <iostream.h>

#include <iomanip.h>

main(){

int sal1 =1000;

int sal2 =1500;

int sal3 =20000;

int sal4 =30000;

int sal5 =60000;

cout << setfill (‘x’) << setw (10);

cout<< sal1<<endl;

cout << setfill (‘x’) << setw (10);

cout<< sal2<<endl;

cout << setfill (‘x’) << setw (10);

cout<< sal3<<endl;

cout << setfill (‘x’) << setw (10);

cout<< sal4<<endl;

cout << setfill (‘x’) << setw (10);

cout<< sal5<<endl;

int i=0;

cin>>i; // to stop the screen to show the output

}

Suppose we have the following class.

class Matrix

{

private:

int Elements[3][3];

};

Write the operator function of stream extraction operator (>>) for this class.

Answer:

Element operator >> (Element &element){

cout<<element[0][0]<<element[0][1]<<element[0][2];

cout<<element[1][0]<<element[1][1]<<element[1][2];

cout<<element[2][0]<<element[2][1]<<element[2][2];

}

Write the general syntax of a class that has one function as a friend of a class along with definition of friend function.

Answer:

class frinedclass{

public:

friend int compute(exforsys e1)

};

Int compute(exforsys e1)

{

//Friend Function Definition which has access to private data

return int(e1.a+e2.b)-5;

}

Question No: 36 ( Marks: 5 )

What are the advantages and disadvantages of using templates?

Answer:

Many things can be possible without using templates but it does offer several clear advantages not offered by any other techniques:

Advantages:

Templates are easier to write than writing several versions of your similar code for different types. You create only one generic version of your class or function instead of manually creating specializations.

Templates are type-safe. This is because the types that templates act upon are known at compile time, so the compiler can perform type checking before errors occur.

Templates can be easier to understand, since they can provide a straightforward way of abstracting type information.

It helps in utilizing compiler optimizations to the extreme. Then of course there is room for misuse of the templates. On one hand they provide an excellent mechanism to create specific type-safe classes from a generic definition with little overhead.

Disadvantages:

On the other hand, if misused

Templates can make code difficult to read and follow depending upon coding style.

They can present seriously confusing syntactical problems especially when the code is large and spread over several header and source files.

Then, there are times, when templates can “excellently” produce nearly meaningless compiler errors thus requiring extra care to enforce syntactical and other design constraints. A common mistake is the angle bracket problem.

Write a program which defines three variables of type double which store three different values including decimal points, using setprecision manipulators to print all these values with different number of digits after the decimal number.

Answer:

#include

#include

main () {

double a = 12.12345;

double b = 13.123456;

double c = 14.1234567;

cout << setprecision (5) << a << endl;

cout << setprecision (2) << a << endl;

cout << setprecision (3) << a << endl;

}

Let we have a class,

class String

{

private:

char buf[25];

};

Write code for assignment (=) operator function which assign one String object to other object. Your code should also avoid self assignment

Answer:

void String::operator = ( const String &other )

{ int length ;

length = other.length();

delete buf;

buf = new char [length + 1];

strcpy( buf, other.buf ); }

Question No: 40 ( Marks: 5 )

Read the given below code and explain what task is being performed by this function Matrix :: Matrix ( int row , int col )

{

numRows = row ;

numCols = col ;

elements = new ( double * ) [ numRows ] ;

for ( int i = 0 ; i < numRows ; i ++ )

{

elements [ i ] = new double [ numCols ] ;

for ( int j = 0 ; j < numCols ; j ++ )

elements [ i ] [ j ] = 0.0 ;

}

}

Hint : This function belong to a matrix class, having

Number of Rows = numRows

Number of Columns = numCols

Answer:

In the above mentioned code, first of all programmer call the constructor who have two parameters for the number of rows & columns in the matrix. Then this constructor also dynamically allocates the memory for the elements of the matrix & also initializes the value of the all elements of matrix with 0.0.