C++ notes.pdf BASIC C++ NOTES FOR BEGGINERS

C++ NOTES

1. Tutorials For
Beginners

2. Introduction to
programming
languages
2
●computer program
●Programming
●Programmer
●Source Code (Code)
●Hardware
●Program Execution
●Machine Language
●Assembly Language
●High Level Language

3. 3
High Level Language

Assembly Language Machine Language

4. 4
Compiler VS Interpreter

5. 5
Compiler
Interpreter

6. 6
Compiler VS Interpreter

Compiler
●Scans whole program at
one go
●Errors are shown at the
end
●Compilation is slow
●Execution is fast
●Generates an intermediate
code
●C,C++
Interpreter
●Translate one statement
at a time(line by line)
●Errors are shown line by
line
●Translation is done fast
●Execution is slow
●Execute the program
without intermediate code
●Python,Javascript

7. 7
To Run C/C++ program we need :
C/C++ Compiler and VS code setup
●Text Editor (VS code)
●C++ compiler (GCC compiler)

●C/C++ - VS code extension
●Code Runner - VS code extension

Extra Setup:

8. 8
How to run
C/C++
program in
mobile ?

9. Basic Structure Of
C++ Program

10. 10
INPUT/OUTPUT
In C++
●CIN and COUT
●Extraction >> and insertion << operator
●endl vs \n
●Code Runner(Extension) issue with CIN

11. Comments in C++
11
●SIngle Line Comment -//
●Multiline Comment - /* */

12. 12
Variables & Data Types
in C++

13. 13
Rules for naming a variable
● Variable names in C++ can range from 1 to 255
characters.
● All variable names must begin with a letter of the
alphabet or an underscore(_).
● After the first initial letter, variable names can also
contain letters and numbers.
● Variable names are case sensitive.
● No spaces or special characters are allowed.
● You cannot use a C++ keyword (a reserved word)
as a variable name.

14. 14

15. Modifiers in C++
15

16. 16
Data Type Size Value Range
int 4 Bytes -2147483648 to 2147483647
char 1 Bytes -127 to 127 or 0 to 255
float 4 Bytes - 3.4E38 to 3.4E38
double 8 Byte - 1.7E308 to 1.7E + 308
bool 1 Byte

17. Modifiers in c++
17
●Signed
●unsigned
●short
●long

18. 18
Data Type Size Value Range
int 4 Bytes -2147483648 to 2147483647
Unsigned int 4 Bytes 0 to 4294967295
signed int 4 Bytes -2147483648 to 2147483647
Sort int 2 Bytes -32768 to 32767
long int 8 Bytes -2,147,483,648 to 2,147,483,647
char 1 Bytes -127 to 127 or 0 to 255
Unsigned char 1 Bytes 0 to 255
Signed char 1 Byte -127 to 127
float 4 Bytes - 3.4E38 to 3.4E38
double 8 Byte - 1.7E308 to 1.7E + 308
long double 12 Bytes - 3.4E4932 to 1.1E + 4932
bool 1 Byte

19. Scope of Variables
in C++
●Local Variables
●Global Variables

20. Constant Variables
●A const variable must be assigned a value at the
time of its declaration.
●If we declare a variable as const, we cannot
change its value.
●Once initialized, if we try to change its value, then
we will get compilation error.

20

21. Manipulators in c++
21
Manipulator Purpose Header File
endl causes line feed to be inserted i.e. ‘\n’

iostream.h
dec,oct,hex set the desired number system iostream.h
setbase (b)

output integers in base b iomanip.h
setw(w) read or write values to w charactersiomanip.h
setfill (c) fills the whitespace with character ciomanip.h
setprecision(n)

set floating point precision to n

iomanip.h

22. Operators in C++
1.Arithmetic Operators
2.Relational Operators
3.Logical Operators
4.Assignment Operators
5.Bitwise Operators
6.Other Operators
22

23. Operators in C++
23

24. 24
Arithmetic Operators
Operator Description Example
+ Adds two operands A+B=30
- Subtracts second operand from the first A-B=10
* Multiplies both operands A*B=200
/ Divides numerator by de-numerator A/B=2
% Modulus operator – the result is the remainder of the
division
A%B=0
++ Increment operator, increases integer value by one A++ will give 21
-- Decrement operator, decreases integer value by one B-- will give 9
Assume A=20 and B=10

25. 25
Relational Operators
Operator Description Example
==
Checks if the values of two operands are equal or not. (A == B) = false
!=
Checks if the values of two operands are equal or not. (A != B) = true
>
Checks if the value of left operand is greater than the value of
right operand
(A>B) = true
<
Checks if the value of left operand is less than the value of right
operand,
(A<B) = false

>=
Checks if the value of left operand is greater than or equal to
the value of right operand
(A>=B) = true
<=
Checks if the value of left operand is less than or equal to the
value of right operand
(A<=B) = false
Assume A=20 and B=10

26. 26
Logical Operators
Operator Description Example
&&
Logical AND. True only if all the operands are true. (A>10 && B>20) = false
||
Logical OR. True if at least one of the operands is true.(A>10 || B>20) = true
!
Called Logical NOT Operator. Use to reverses the
logical state of its operand. If a condition is true, then
Logical NOT operator will make false.
!(A>10) = false
Assume A=20 and B=10

27. 27
Logical Operators
A B A && BA|| B !A
false false false false true
false true false true true
true false false true false
true true true true false

28. 28
Assignment Operators
Operator Description Example
=
Assigns values from right side operands to left side
operand.
A =5
+=
It adds right operand to the left operand and assign the
result to left operand
A +=5 same as A=A+5
-=
It subtracts right operand from the left operand and
assign the result to left operand.
A-=5 same as A=A-5
*=
It multiplies right operand with the left operand and
assign the result to left operand.
A*=5 same as A=A*5

/=
It divides left operand with the right operand and assign
the result to left operand.
A/=5 same as A=A/5
%=
It takes modulus using two operands and assign the
result to left operand.
A%=5 same as A=A%5

29. 29
Bitwise Operators
A B A&B A|B A^B ~A
0 0 0 0 0 1
0 1 0 1 1 1
1 0 0 1 1 0
1 1 1 1 0 0

30. 30
Bitwise Operators
Operator Description Example
&
Binary AND Operator copies a bit to the result if it exists in
both operands.
(A & B) = 1 (00000001)
|
Binary OR Operator copies a bit if it exists in either operand.(A | B) = 3 (00000011)
^
Binary XOR Operator copies the bit if it is set in one operand
but not both.
(A ^ B) = 2 (00000010)
~
Binary Ones Complement Operator is unary and has the
effect of 'flipping' bits.
!A=!3= -4 (11111100)

<<
Binary Left Shift Operator. The left operands value is moved left
by the number of bits specified by the right operand.
A<<1 = 6 (00000110)
>>
Binary Right Shift Operator. The left operands value is moved right by
the number of bits specified by the right operand.
A>>1 = 1 (00000001)
A=3 (0000 0011 ) and B=1 (0000 0001)

31. 31
Other Operators
Operator Description Example
sizeof
Returns the size of variable sizeof(int) =4
Condition ? x:y
If condition is true then it returns value of X
otherwise returns value of Y
Int y=20;
int x= (y < 10) ? 30 : 40;
cast
Convert one data type to other int(2.2000) = 2
,
causes a sequence of operations to be
performed. The value of the entire comma
expression is the value of the last expression
of the comma-separated list.
Int j=1;
int i= (j++, j+10, j+20);
&
Returns the address of a variable
*
Is pointer to a variable

32. 32
Operators Precedence and Associativity
Category Operator Associativity
Postfix () [] -> . ++ - -
Left to right
Unary + - ! ~ ++ - - (type)* & sizeof
Left to right
Multiplicative * / %
Left to right
Additive + -
Left to right
Shift << >>
Left to right
Relational < <= > >=
Left to right
Equality == !=
Left to right
Bitwise AND &
Left to right

33. 33
Operators Precedence and Associativity
Category Operator Associativity
Bitwise XOR ^
Left to right
Bitwise OR |
Left to right
Logical AND &&
Left to right
Logical OR ||
Left to right
Conditional ?:
Right to left
Assignment = += -= *= /= %=>>= <<= &= ^= |=
Right to left
Comma ,
Left to right

34. Increment (++) and decrement (--)
34
1.The increment operator ++ increases the value of a variable
by 1
2.Similarly, the decrement operator -- decreases the value of a
variable by 1
3.Increment and decrement operators can be used only with
variables. They can't be used with constants or
expressions.
Eg. x=5,y=6;
x++; // valid
5++; // invalid
(x+y)++; // invalid

35. Types of Increment ++ operator
35
Increment ++
Post-increment
Eg. a++
Pre-increment
Eg. ++a
1.In pre-increment first increment the value of variable and then
used inside the expression (initialize into another variable).
2.In post-increment first value of variable is use in the expression
(initialize into another variable) and then increment the value of
variable.

36. Types of decrement -- operator
36
decrement --
Post-decrement
Eg. a--
Pre-decrement
Eg. --a
1.In pre-decrement first decrement the value of variable and then
used inside the expression (initialize into another variable).
2.In post-decrement first value of variable is use in the expression
(initialize into another variable) and then decrement the value of
variable.

37. 37
●If-else
●Switch
●For Loop
●While loop
●Do-While Loop
●Break /Continue
●Goto
Control Statement

38. 38
●If statement
●If...else statement
●If…else if…else statement
●Nested if statement

If-else

39. 39
●Write a C++ program to accept two integers and check whether they are
equal or not.
●Write a C++ program to accept a integer and check whether number is
even or odd.
●Write a C++ program to accept a integer and check whether number is
positive,negative or zero.
●Write a program in C++ to read any day number in integer and display day
name in the word.
●Write a C++ program to accept two integers and find maximum between
two numbers.

If-else practice questions :

40. 40
switch-case

41. 41
Switch-case practice questions :
●Write a C++ program to print day of week name using switch case.
●Write a C++ program print total number of days in a month using switch
case.
●Write a C++ program to accept a integer and check whether number is
positive,negative or zero using switch case.
●Write a program in C++ to read any day number in integer and display day
name in the word using switch case.

42. 42
Loops in C++ :
●For loop
●While loop
●Do-while loop

43. 43
For loop :
Syntax :
for(initialization;condition;increment){
// your code
}
Example:
for(int i=0;i<5;i++){
cout<<i<<”\n”;
}

44. 44
While loop :
Syntax :
while(condition){
// your code
}
Example:
int i=0;
while(i<10){
cout<<i<<”\n”;
i++;
}

45. 45
do-while loop :
Syntax :
do{
// your code
}while(condition)
Example:
int i=0;
do{
cout<<i<<”\n”;
i++;
}while(i<10)

46. 46
Loop practice questions :
●Write a program in C++ to find the first 10 natural numbers
○1 2 3 4 5 6 7 8 9 10
●Write a program in C++ to print a square pattern with # character.




●Write a program in C++ to find the factorial of a number.
●Write a program in C++ to display the pattern like right angle triangle using
an asterisk.

47. 47
Loop practice questions :
●Write a program in C++ to display the pattern like right angle triangle using
an asterisk.



●Write a program in C++ to make such a pattern like a pyramid with an
asterisk.

48. 48
Break
●In C++, the break statement terminates the loop when it is encountered.

49. 49
Continue
●In C++, the continue is used to skip the current iteration of the loop and the
control of the program goes to the next iteration

50. C++ Functions
50

51. C++ Functions
51
●A function is a block of code that performs a specific task.
●Functions help us in reducing code redundancy.
●If functionality is performed at multiple places in software,
then rather than writing the same code, again and again, we
create a function and call it everywhere.
●This also helps in maintenance as we have to change at one
place if we make future changes to the functionality.

52. C++ Functions
52
●There are two types of function:
○Library Functions (Built in functions)
○User defined functions
●Function declaration
returnType functionName (parameter1, parameter2,...) {
// function body
}

53. Function Prototype
53
●The code of function declaration should be before the
function call.
● However, if we want to define a function after the function
call, we need to use the function prototype.
●Function prototype is a declaration statement.
type function-name (arguments-list);
Eg. int sum(int num1,int num2);
OR
int sum(int,int); // Variable name is optional

54. Default Parameters
54
●In C++, we can provide default values for function parameters.
●In this case, when we invoke the function, we don’t specify
parameters.
●Instead, the function takes the default parameters that are
provided in the prototype.
●Note that while providing default parameters, we always start from
the right-most parameter. Also, we cannot skip a parameter in
between and provide a default value for the next parameter.
●Eg.
Void add(int x, int y, int z = 0)
Default parameter

55. Const Parameters
55
●We can pass constant parameters to functions using the
‘const’ keyword.
●When a parameter or reference is const, it cannot be
changed inside the function.
Void add(const x, const y)
Const parameter

56. Inline Functions
56
●When we make a function call, internally it involves a compiler
storing the state of the program on a stack before passing
control to the function.
●When the function returns, the compiler has to retrieve the
program state back and continue from where it left.
●This poses an overhead. Hence, in C++ whenever we have a
function consisting of few statements, there is a facility that
allows it to expand inline.
●This is done by making a function inline. So inline functions are
the functions that are expanded at runtime, saving the efforts to
call the function and do the stack modifications.

57. Inline Functions
57
● But even if we make a function as inline, the compiler
does not guarantee that it will be expanded at runtime.
●In other words, it’s completely dependent on the compiler
to make the function inline or not.
●Eg.
inline int addition(const int a,const int b)