CLASS XI CPP NOTES

7/29/2019 CLASS XI CPP NOTES

1/27

C++ Notes

What is C++?

C++ is an object-oriented programming language. It was developed by Bjarne Stroustrup at

AT&T Bell Laboratories in Murray Hill, New Jersey, USA, in the early 1980s.

Conversion of source program to executable fileThe conversion of a source file into an executable file is a two step process:

1. First you compile your source file into an object file.2. Link it with necessary library routines.

Source Code/File: The program written in a programming language like C++ is called asource file, or source code. It is not an executable file. In C++ it has .CPP extension.

Object Code/File: Object code/file is the representation of codes that compiler orassembler generates by processing a source code/file. Object files contain compact

code, often called binaries. Its extension in DOS is .OBJ.

Executable Code/File: Executable code/file, in computer science, is as file whosecontents are meant to be interpreted by operating system. Its extension in DOS is .EXE.

Compiler: It is a program which converts the program written in a programminglanguage to a program in machine language. Every programming language has its own

compiler.

Linker: It is a program which takes a compiled program to the necessary library routines,to make it an executable program.

Compiling: The process of converting the source program into an object program iscalled compiling. In this, program written in any programming language is converted into

the machine language with the help of compiler.

Linking: The process of converting the object program into an executable program iscalled linking. In this the program in machine language instruction is linked with

necessary library routines, with the help of linker.

Prog1.CPP

Prog1.OBJ

Prog1.EXE

COMPILER

SOURCE FILE

LINKER

OBJECT FILE

EXECUTABLE FILE


2/27

C++ Notes

C++ Character set: It is a set of characters that can be used in C++ program. It consists ofalphabets (A..Z, a..z), digits (0 ...9), and special characters (&, :, ;, *, space etc).

C++ Tokens: A Token is a group of characters that logically belong together. It is thesmallest individual unit in a program. C++ supports the following types of tokens:

a) Identifier: It is a symbolic name given by a programmer for any data item orfunction. The identifier is a sequence of characters takes from C++ character set. The

rules for formation of identifier are:

Can consist of alphabets, digits and special character underscore ( _ ). Can start with an alphabet or underscore, but not with digit. C++ is case sensitive. Blank space not allowed

b) Variable: It is a location in the computer memory which can store data and is given asymbolic name for easy reference. Its value can change during program execution.The syntax for declaring a variable:

[ = ],. ; Example :

char grade;

int a, b=10, c;

Data type has to be any one of the data types present in C++. The basic data types

available in C++ are:

Data

Types Range

Size

(Bytes) Usages

char 0 to 255 1 For storing Characters

int -32768 to 32767 2 For storing numbers without decimal

long -2,147,483,648 to 2,147,483,647 4 For storing numbers without decimal

float - 3.4 x 1038

to 3.4 x 1038

- 1 4For storing floating point numbers. It

has seven digits of precision.

double - 1.7 x 10308

to 1.7 x 10308

- 1 8For storing floating point numbers. It

has fifteen digits of precision.

long

double- 3.4 x 10

4932to 3.4 x 10

4932- 1 10

For storing floating point numbers. It

has nineteen digits of precision.

c) Keywords: A keyword is a reserved word that has a predefined meaning and purposein the language. It cannot be used as an identifier by the user in this program. e.g.

float

d) Constant: It is an identifier whose value does not change during program execution.The syntax for declaring a constant is

const = ; For e.g. const float pi = 3.14;


3/27

C++ Notes

e) Operators: An operator is a symbol or letter used to indicate a specific operation onvariable or value in a program. There are three types of operators in C++:

Unary operators: Operators which operate on one operand. For e.g. Theincrement (++), the decrement (--), and logical NOT (!) are the unary operator.

Binary operators: Operators which operate on two operands are called binaryoperators. For example, all arithmetic operators, all relational operators and

logical AND (&&), and OR (||) are the binary operators.

Ternary Operators: Operators which operate on three operands are calledternary operators. For example, the conditional (? : ) operator is a ternary

operator.

f) Punctuators/Separators: The following characters are used as punctuators/separators inC++: ( ) { } , ; : * # [ ]

# : It is called the preprocess directive in C++. A preprocessor directive is an instructionto the compiler itself. A part of the compiler called preprocessor, deals with thesedirectives, before real compilation process.

The #include directive: The preprocessor directive #include tells the compiler to insertanother file into your source file. In effect, the #include directive is replace by the

contents of the file indicated.

Output using cout: cout statement is used to display a value on screen. The cout isalways used with the insertion operator (


4/27

C++ Notes

For example: coutb>>c;

Assignment Operator ( = ): The equal sign, causes the value on right to be assigned to be

assigned to variable on the left. The statements which assign values to variables are called

assignment statements.Syntax:

Variable = value/variable/expression

Example: a = 10;

Arithmetic Operator: The arithmetic operators available in C++ are:

Operator Usage

+ Used for Addition

- Used for Subtraction

* Used for multiplication

/ Used for division

%

This operator is called the remainder or the modulus operator. It is used to find

the remainder when one integer value/variable is divided by another

value/variable. This operator cannot be used with floating type variables/values.

For e.g.

int a=10, b=3;

cout


5/27

C++ Notes

Logical Operators: Two conditions can be logically combined with the help of logical

operators. The logical operators present in C++ are:

Operator Usage Example

&& AND

The compound condition evaluates to true,

if both the conditions in the compound

condition evaluate to true.

((a>b) && (a>c))

|| OR

The compound condition evaluates to true,

if any or both the conditions in the

compound condition evaluate to true.

((a>b) || (a>c))

! NOT

It negates the condition. That is:

If the condition evaluates to true, itmakes it false.

If the condition evaluates to false, itmakes it true.

!(a>b)

Arithmetic Assignment Operators (Shorthand Operators): Arithmetic assignment operator,

is one,, which combines arithmetic operator and an assignment operator. The arithmetic

assignment operators present in C++ are:

Operator Example Meaning

+= A += B; A = A + B;

-= A -= B; A = A - B;

*= A *= B; A = A * B;

/= A /= B; A = A / B;

%= A %= B; A = A % B;

Increment/Decrement Operators (Unary Operator):

Increment ( ++ ) Operator: It is used to increment the value of variable by 1. It can be used

in the following two ways:

Pre Increment Post Increment

In this, the operator precedes the variable.

Example: ++a

In this, then operator follows the variable.

Example: a++

b = ++a;

This statement is equivalent to the following

two statements:

a = a + 1;

b = a;

So, in pre increment the value of the variable

is incremented, before it is used in any other

operation (Assignment in this case)

b = a++;


two statements:

b = a;

a = a + 1;

So, in post increment the value of the

variable is incremented, after it is used in

any other operation (Assignment in this

case)


6/27

C++ Notes

Decrement (--) Operator: It is used to decrement the values of variable by 1. It can be used

in the following two ways:

Pre Decrement Post Decrement

In this, the operator precedes the variable.

Example: --a

In this, then operator follows the variable.

Example: a--

b = --a;


two statements:

a = a - 1;

b = a;

So, in pre decrement the value of the

variable is decremented, before it is used in

any other operation (Assignment in thiscase)

b = a--;


two statements:

b = a;

a = a - 1;

So, in post decrement the value of the

variable is decremented, after it is used in

any other operation (Assignment in thiscase)

Conditional Operator (? : ): The question marks (?) and the colon (: ) make up the

conditional operator. The operator operates on three operands that are why it is called the

ternary operator. The whole expression is called the conditional expression. The expression

before the question mark is called the test expression. If the test expression is true, then the

entire conditional takes on the value of the operands after the question mark. If the test

expression evaluates to false, then the conditional expression takes on the value of the

operand following the colon.

Syntax:

? :

Example:

res = ( x < y ) ? x : y;

In the above example, if the test expression evaluate to true the variable res will be assigned

the value of the variable after the question mark, i.e. x else it will be assigned the value of

the variable after the colon i.e. y.

Example:

cout


7/27

C++ Notes

Conversion: Automatic Type conversion: When two operands of different data types are

encountered in the same expression, the variable of lower data type is automatically

converted to the data type of variable with higher data type, and then the

expression is calculated.

For Example:

int a=98;

float b=5;

cout


8/27

C++ Notes

else

{

Statement 1;

:

Statement N;

}

{

cout


9/27

C++ Notes

Syntax Example

switch ( )

{

case : Statement 1;

:

Statement n;

case : Statement 1;

:

Statement n;

case : Statement 1;

:

Statement n;

case : Statement 1;

:

Statement n;:

:

default : Statement 1;

:

Statement n;

}

Note: default case is optional.

switch(color)

{

case 3: cout


10/27

C++ Notes

Manipulators: Manipulators are operators used with the insertion operator (


11/27

C++ Notes

example 1(a) the loop continues if the value of a


12/27

C++ Notes

While Loop:

The while loop executes a section of the program till a specified condition is true. While loop

is used when the number of times the loop is to be executed is not known. The condition is

always checked first before the loop is executed.

Syntax:

while()

{

statement 1;

statement 2; Loop Body

:

statement n;

}

Examples:

1. while-loop with a single statement 2. The execution of the following loop

depends on the value of Ans, therefore the

number of times the loop is executed is notknown.

int a=1;

while (a


13/27

C++ Notes

1. 2.

int a=1;

do

{

cout


14/27

C++ Notes

Nested Loops:

When a for, while or do..while loop is used inside another looping construct, the concept is

called a nested loop. This concept is used whenever for each repetition of a process many

repetitions of another process are required.

Some sample skeletal structures ofNested Loopsfor( .. )

{

for( .. )

}

while( .. )

{

while( .. )

}

Do

{

while( .. )

}

while( .. );

do

{

for( .. )

}

while( .. );

Example:

for( int p = 1; p


15/27

C++ Notes [Function]

Function: A function is a named unit of a group of statements that can be invoked from

other parts of the program. The advantages of using functions are:

Functions enable us to break a program down into a number of smaller and smaller andsimpler units. This makes the program more organized and structured and easier to

debug.

It helps in reusability of code and thus reduces program size. If similar code is requiredat several places in the program, the use of a function allows this code to be written just

once, and to be called wherever it is required.

It helps to execute the same set of statements with different set of values.Function Declaration/Prototype: Just as any variable is declare before it is used in a

program, it is necessary to declare a function to inform the compiler that the function would

be referenced at a later point in the program. Function declaration is also called function

prototype.

Syntax for function declaration:

( [], . );

Example: int sum ( int, int);

A declaration (prototype) tells the compiler that later on in our program we are going to

write a particular function. It also informs the compiler about:

1. the type of result to be returned;

2. the identifier of the function;

3. the number and types of parameters;

It is terminated by a semicolon.

: It is the data type of the value that is returned to the calling function after

the function is executed. It can be any of the data types, available in C++.

: It is the name of the function, which is given with accordance to the

naming conventions used for naming an identifier. A function is called with the help of its

name.

: These are the data types of the parameters/inputs that the

function receives when it is called. In function declaration it is optional to give the name of

the parameters. The different data types specify to the compiler, the total number of

parameters, and the data type of these parameters that the function will receive, when it is

called (invoked).

Function definition: The function definition contains the function header and the function

body i.e. the set of statements which are executed when the function is called.

Syntax for function definition:

(


16/27


return ( value / variable / expression );

}

Example:

int sum ( int a, int b)

{

int s = a + b;

return s;

}

Note: The return statement is used to return a value to the calling function. It is always the

last statement in the function definition (if the function has return type). The data type of

the value returned should match with the return type of the function.

// Example 1

// Program to find the factorial of a number using a function Fact ()

#include

#include

long Fact( long); // Function Prototype

void main()

{

long num;

clrscr();

coutnum;

cout


17/27


Function Header: It is the first line of the function definition, which specifies the following:

Return type of the function Name of the function Name of the parameters, along with their data types

Note: It is not terminated with semicolon.

Function Body: It is the set of statements, which are executed when the function is called.

Function Call: It is the statement in the calling function, through which the control is passed

to the function definition of another function. This will execute the statements is the called

function and then the control is returned back to the statement in the calling function,

which follows the function call statement. The function call consists of the function name,

followed by actual parameters, if any, enclosed in parentheses.

Calling Function: The function, which calls a function is called the calling function. In the

above example main() is the calling function.

Called Function: The function which is called by anther function is known as the called

function.

Formal Parameter: The parameters mentioned in the function header are called formal

parameter.

Actual Parameter: Values/Variables which are used while making a call to the function are

called actual parameter.

Difference between call by value and call by reference

Call by Reference Call by Value

1) The changes made to the formal

parameters are reflected back to the actual

parameters.

1) The changes made to the formal

parameters are not reflected back to the

actual parameters.

2) It provides a mechanism of returningmore than one value.

2) Not Available

3) The reference parameters require an

ampersand (&) sign before their name.

3) Not Available

4) The Formal and Actual parameters share

the same memory location.

4) The formal and actual parameters have

different memory location.

5) void Swap(int & a, int & b){

int temp = a;

a = b;

b = temp;}

5) void Swap(int a, int b)

{

int temp = a;

a = b;

b = temp;}

// Program to illustrate the invoking of a function using call by value

// and call by reference methods

#include

#include

// Function to swap the values of two variables,

// where both the parameters are value parameters

void swapv ( int a, int b)

{

int temp = a;

a = b;


18/27


b = temp;

cout


19/27


void main()

{

clrscr();

int a,b,c;

couta>>b;

c = Sum(a,b); // Function call statement, the returned value is stored in the variable c

cout


20/27


In-Built functions in Header File

Function Usage Example Result

1. fabs(x) Calculates the absolute value

of the floating point number x.

cout


21/27


cout


22/27


}

}

return lcm;

}

int GCD(int a, int b)

{

int i, gcd;

for(i=1; i>b;

l = LCM(a,b);

cout


23/27

What is difference between Actual Parameters and Formal Parameters? Give an

example in C++to illustrate both types ofparameters.

ActualParameter Formal ParameterA parameterused in a function call isknown as actual parameter. It is used tosend data to function.

A parameterused in a functiondefinition is known as formal parameter.It is used to accept data from actualparameters.

Void abc(int a) // a is formal parameter{Int x=9;x=x+a;}Void main(){Int p=6;abc(p); } // p is actual parameter

What do you mean by function prototyping? Write down the advantages of

function prototypes in C++?

Ans. Function prototyping means writing the function prototypes before their

function call occurs. A function prototype is a declaration of the function tells the

program about the type of the value re tu rned by the function and the numberand

type of arguments. The advantage of function prototyping is that it enables a

compiler to compare each use of function with the prototype to determine whether

the function is invoked properly or not. The numberand types of arguments can be

easily compared and any wrong number of types of the argument is reported.

Therefore, function prototyping makes C++straightaway point to the error.

How is global prototype different from a local prototype?

Ans. Ifa function prototype is placed in the body ofanother function, it is local

prototype and the function is locally available to the function that declares it.

Ifa function prototype is placed outside all the functions, it is global prototype and

the function is globally available to all the functions.


24/27

-------------------------------------------------------------------------------------------------------

Sample Paper Computer science

Class: XI------------------------------------------------------------------------------------------------------------Time Duration: 3 Hours Maximum Marks: 70

------------------------------------------------------------------------------------------------------------

Instructions:

All Questions are Compulsory.

I. 1. Name different types of digital computers based on their size and performance. [1]2. What is system software? [1]

3. Explain first come first served (FCFS) scheduling. [2]

4. Explain multiprocessing operating system. [2]

(Total: 6M)II. 1. Differentiate between syntax error and semantics error. Give example for each. [2]

2. What do you mean by robustness of a program? What is guard code? [2]3. What is a base class? What is a derived class? How are these two interrelated? [3]

4. Explain:

a.) Encapsulationb.) Transitive nature of inheritance

c.) portability [3]

(Total: 10M)

III. 1. Convert the following binary number to decimal:a) 101.1001 b) 11101.111

2. Convert the following octal values to decimala) 1204.3 b) 743

3. Convert the following decimal values to hexadecimal:

a) 314.21 b) 2048

4. Convert the following decimal values to binary:

a) 57.31 b) 29.25. Convert the following binary number to hexadecimal:

a) 1010110110111 b) 10110111011011 (1M X 5 =5M)

6. Differentiate between:

a) RAM and ROM b) impact printer and non impact printer. [4]7. What is a port? [1]

(Total: 10M)

IV. 1. Determine then output if the input is:

( a ) 2000 ( b ) 1900 ( c ) 1971

void main( ){

int year;

cin>>year;

if ( year%100 = =0)


25/27

-------------------------------------------------------------------------------------------------------

{

if ( year % 400 = =0)

cout


26/27

-------------------------------------------------------------------------------------------------------

4. What is the effect of absence of break in a switch statement? Can the case labels

in a switch have identical values?

5. Rewrite the following code fragment using switch:

void main ( ){

if (ch = = E)

cout


27/27

f * = i;

cout

Date post:	03-Apr-2018
Category:	Documents
Upload:	vibhor-kaushik
View:	226 times
Download:	0 times

CLASS XI CPP NOTES

Documents