C programming, RTS Tech. Indore This is a presentation to take your skills to next level. Hope you will like our work to make programming easier for you. Feel free to contact for the online/offline batches.

1. RTS tech. 1

2. Features of C
 It is simple and easy to use.
 It is Primitive Programming Language.
 It is structured programming language.
 It is used in many popular application such as : Linux,
Unix, MySQL etc…
 It is platform independent.
 It is case sensitive.
 It is Fast.
 It is Mid Level Programming Language.
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3. Learning Strategies
 Learning Natural Language
 Learning Computer Language:
RTS tech. 3
Alphabets Words Sentences Paragraph
Character Set Keywords Statements Program

4. What is Program?
 Program is a step by step solution to a problem.
 Program contains :
 Data(variables): To store the human data
 Function: to perform action on stored data
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5. Structure of C Program
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6. Library in c
 It is a collection of Reusable programs.
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7. Lets start coding.
 //header file
 # include <stdio.h>
 //main function
 void main(){
 // to print output
 printf(“Hello world!!!”);
 }
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8. Basic Building Block
 #include <stdio.h>: is a header file for input
and output functions.
 void : it is a keyword which means nothing.
 main(): it is a entry point of the program.
 printf(): it is a in-built function to print output
on the console screen.
 // : it is used to write comments. Comments not take
parts in execution.
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9. How to compile and run ?
 Save the file by the name Hello.c
 Open command Prompt and compile the file.
 C:>gcc Hello.c –o Hello
 This command will generate Hello.exe file
 Execute/Run
 c:>Hello.exe
RTS tech. 9
Hello.c Compile Hello.exe

10. Compilation process of C
 C:>gcc –Wall –save-temps test.c –o test
 Run the command to generate the
following files
 Expanded code file (.i) extension
 Assembly code file (.a) extension
 Object code file(.obj) extension
 Executable code file. (.exe) extension
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11. printf() function
 This function is sued to write the text on the console window.
 Format of printf():
 printf(“format string”, argument list);
 Format Strings are:
 “%d”: it is used to write int
 “%f”: ”: it is used to write float
 “%c”: ”: it is used to write character
 “%lf”: ”: it is used to write double
 “%u”: for unsigned int
 “%Lf”: for long double
RTS tech. 11

12. scanf() function
 This function is used to receive inputs.
 We can enter the data from the keyboard.
 ‘&’ symbol is must in the scanf function to read the data.
 & is an “Address of” operator.
 For ex.
 int a;
 Scanf(“%d”,&a);
 Above statement will read the integer value from the
keyboard and stores it into variable a.
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13. Use of scanf()
 #include <stdio.h>
 int main(){
 int a;
 printf("Enter a no n");
 scanf("%d",&a);
 printf("Squre of entered No is : %dn",a*a);
 return 0;
 }
RTS tech. 13

14. Variables in C
 Variables are the name of the
memory Locations.
 It is sued to store data.
 Variables has different sizes
according to the Data type.
 We can access the value by
variable name from the
computer memory.
 Declare a variable:
 data_type var_name=value
14
30
int x=30;
Memory
X
Data_type var_name value
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15. Basic data Types
 #include<stdio.h>
 void main(){
 int i=2;
 char ch='A';
 float f=2.3f;
 double d=4.567789;
 short int s=2;
 printf("%dn",i);
 printf("%fn",f);
 printf("%lfn",d);
 printf("%cn",ch);
 printf("%dn",s);
 }
RTS tech. 15

16. Data Types
 Data type is used to define the type of the data.
 Size can be vary compiler to compiler
RTS tech. 16
Types Data Type
Basic int,char, float, double
Derived array, structure, pointer,
union
Enumeration enum
void void

17. Data type Modifiers
 It is used to modify the size of the Data types.
 C provides the 4 Modifiers:
 short: short integer no
 short int a=1;
 long: large integer no.
 long int a=5678;
 Long double a=2.345667;
 Signed: contains positive(+) and negative(-) values.
 signed int a=-2;
 Unsigned: It accept only positive values.
 unsigned int =+5;
RTS tech. 17

18. Get The size of the Data Types
 #include<stdio.h>
 void main(){
 int i=2;
 char ch='A';
 float f=2.3f;
 double d=4.567789;
 short int s=2;
 printf("Size of int %dn",sizeof(i));
 printf("Size of float %dn",sizeof(f));
 printf("Size of double %dn",sizeof(d));
 printf("Size of char %dn",sizeof(ch));
 printf("Size of short int %dn",sizeof(s));
 }
RTS tech. 18

19. All data types
Data Type Range Bytes Format
signed char -128 to +127 1 %c
unsigned char 0 to 255 1 %c
short signed int -32768 to +32767 2 %d
short unsigned int 0 to 65535 2 %u
signed int -2147483648 to +2147483647 4 %d
unsigned int 0 to 4294967295 4 %u
long signed int -2147483648 to +2147483647 4 %ld
long unsigned int 0 to 4294967295 4 %lu
float -3.4e38 to +3.4e38 4 %f
double -1.7e308 to +1.7e308 8 %lf
long double -1.7e4932 to +1.7e4932 10 %Lf
RTS tech. 19

20. Keywords
 Keywords are reserved words.
 We can not use them to define user defined variables and
function.
RTS tech. 20

21. Identifiers
 It is a name of the
 Variables
 Function
 array
 Structure
 Union…
 We can access the variables by the name.
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22. Rules to define the Identifiers
 It can start with alphabets and _under score.
 It cannot start with a digit. int 123test;
 It does not contains special symbols excluding
_underscore. int @name;
 It can precede with a digit. For ex. int test123;.
 We can not use keywords as identifiers.
 It is case sensitive.
 int a=10;
 int A=20; both are different for c.
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23. Operators
 Operators are symbol which perform some operation
when applied.
 We can categorize them according to the performed
operation like:
 Arithmetic Operators,
 Logical Operators,
 Bitwise operators
 Relational operators.
 etc…
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24. Precedence of Operators
 3+4+6
 3-2*10
 A=2+3*4
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25. Types of Operators and precedence
RTS tech. 25

26. Unary Operators
 () !
 ~ +(unary)
 sizeof() -(unary)
 ++ --
RTS tech. 26

27. Binary Operator
It operates on two variables.
X (op) Y
RTS tech. 27
Operands
Operator

28. Arithmetic Operators
Addition
Subtraction
Division
Multiply
Reminder
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+
-
/
*
%

29. Relational operators
<
>
<=
>=
!=
==
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Less Than
Greater Than
Less than equal
Greater than equal
Not equal
Equal to

30. Compound Operators
+=
-=
/=
*=
%=
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Add Assign
Subtract Assign
Divide Assign
Multiply Assign
Reminder Assign

31. Logical Operators
Logical And
&&
Logical OR
||
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32. Bitwise Operators
RTS tech. 32
<<
>>
~
&
|
^
Left shift
Right shift
Bitwise complement
Bitwise AND
Bitwise OR
Bitwise XOR

33. Unary bitwise complement
1 1 1 1 0 1 0 1
~
1 Byte
RTS Tech. 33
0 0 0 0 1 0 1 0
byte a = 10;
byte b = ~a;
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34. Left Shift <<
1 1 1 0 0 1 0 1
<<
1 Byte
1 0 0 1 0 1 0 0
byte a = 10;
b = a<<2;
RTS Tech. 34
RTS tech.

35. Right Shift >>
1 1 1 0 0 1 0 1
>>
1 Byte
1 0 0 1 1 0 0 1
byte a = 10;
b = a>>2;
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RTS tech.

36. And bitwise &
1 1 1 0 0 1 0 1
&
1 Byte
RTS Tech. 36
0 0 1 1 1 0 0 1
byte a = 10;
b = 20;
c = a & b;
0 0 1 0 0 0 0 1
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37. OR bitwise |
1 1 1 0 0 1 0 1
|
1 Byte
37
0 0 1 1 1 0 0 1
byte a = 10;
b = 20;
c = a | b;
1 1 1 1 1 1 0 1
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38. XOR bitwise ^
1 1 1 0 0 1 0 1
^
1 Byte
38
0 0 1 1 1 0 0 1
byte a = 10;
b = 20;
c = a ^ b;
1 1 0 1 1 1 0 0
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39. Conditional operator
 It is also known as Ternary Operator.
 It is like if then else
 If (a<b) then a else b
 Result=(a<b)?a:b
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40. Type casting
 Conversion from one data type to another data
types.
 It can be done in two ways:
 Implicit: by compiler
 Explicit: by programmer
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41. Implicit type conversion
 It is automatically done by the compile.
 int x=5;
 double d=x;
 short int s=3;
 int i=s;
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42. Explicit type conversion
 It is done when some data loss is considerable.
 It is done by the programmer.
 double d=5.8;
 int i=(int)d;
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43. Constant in c
 Constant has fixed value, we can not change in the
program.
 We can create different kind of constant like int, float,
double, char, string etc.
 There is 2 ways to define constant in c
 Using const keyword
 const int AVG_AGE=60;
 Using #define preprocessor.
 #define PI 3.14
RTS tech. 43

44. Literals?
 Literal are the fixed value which is assigned to a
constant variable.
 Types of Literals:
 Integer
 int x=5;
 Float
 float f=5.6;
 Double
 double d=6.789;
 Character
 Char ch=‘A’;
RTS tech. 44

45. Control statements
 If-else
 while
 do-while
 for
 switch
 break
 continue
 goto.
RTS tech. 45

46. If-else
 #include<stdio.h>
 int main(){
 int age =0;
 printf("Enter age:n");
 scanf("%d",&age);
 If(age>=18){
 printf(“you can voten”);
 }else{
 printf(“You can not voten”);
 return 0;
 }
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47. While Loop
 It is a conditional loop.
 It executes till the condition is true.
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48. While loop (cont.)
 #include <stdio.h>
 #include <stdbool.h>
 int main(){
 int check;
 bool light_is_on=true;
 while(light_is_on){
 printf("Read a bookn");
 printf("Enter 0 if light has gonen");
 scanf("%d",&check);
 if(check==0){
 light_is_on=false;
 }
 }//end of while
 printf("Light has gone you can not readn");
 return 0;
 }
 RTS tech. 48

49. For loop
 It is a counter loop.
RTS tech. 49
How
Many
lives
to
play

50. For loop (cont.)
 #include <stdio.h>
 int main(){
 For(int lives=1; lives<=5; lives++){
 printf("Play game =%d timesn",lives);
 }
 printf("No more lives to play");
 }
RTS tech. 50

51. do-while loop
 It is also a conditional loop
 #include <stdio.h>
 int main(){
 int i=11;
 do{
 printf("%dn",i);
 i++;
 }while(i<=10);
 }
RTS tech. 51

52. Break & continue
 for(int =1; i<=5; i
++){
 if(i==3){
 continue;
 }
 printf(“%dn",i);
 }
 for(int =1; i<=5; i
++){
 if(i==3){
 break;
 }
 printf(“%dn",i);
 }
RTS tech. 52

53. goto statement
 It is a jump statement.
 Which is used to transfer the code to the specified
level.
 Not preferable because it makes program less
readable.
 it must be use in to break the multiple loop in some
condition.
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54. goto (cont.)
 #include <stdio.h>
 int main(){
 for(int i=1; i<=5; i++){
 for(int j=1; j<=5; j++){
 if( i==3){
 goto outer;
 }
 printf("%d",i);
 }printf("n");
 }
 outer: printf("outside the loop");
 }
RTS tech. 54

55. Decision using switch
 #include <stdio.h>
 int main(){
 int i=2,j=3,ch;
 printf("enter 1 for additionn");
 printf("enter 2 for subtractionn");
 scanf("%d",&ch);
 switch(ch){
 case 1:
 printf("Addition of %d and %d is=%dn",i,j,i+j);
 break;
 case 2:
 printf("Subtraction of %d and %d is=%dn",i,j,i-j);
 break;
 default:
 printf("Not a valid operationn");
 }return 0;
 }
RTS tech. 55

56. Character is also allowed
 #include<stdio.h>
 int main(){
 char ch;
 scanf("%c",&ch);
 printf("%c",ch);
 switch(ch){
 case 'A':
 printf("case An");
 break;
 case 'B':
 printf("Case Bn");
 default:
 printf("Default casen");}
 return 0;
 }
RTS tech. 56

57. String
 A string is a 1-dimensional character array ending with null
character(0).
 Each character occupies 1 byte memory.
 String constant is enclosed by double quotes.
 Char[] ch=“RTS Tech.”
 %s format specification is used to print and to get input as
string.
 scanf() function is not capable of receiving multiword
string.
 To receive multi word string we have gets() function.
 Counterpart of gets is puts which is used to print a single
string at a time
RTS tech. 57

58. String as character array
 char ch[]={'R','T','S','T','e','c','h',
'0'};
RTS tech. 58
R T S T e c h 0
0 1 2 3 4 5 6 7

59. String implementation as array
 #include<stdio.h>
 int main(){
 char ch[]={'R','T','S‘,'0'};
 printf("%sn",ch);
 return 0;
 }
RTS tech. 59

60. gets() & puts()
 #include<stdio.h>
 int main(){
 char name[30];
 printf("Enter Your namen");
 gets(name);
 puts(name);
 return 0;
 }
RTS tech. 60

61. String Functions
 #include<stdio.h>
 #include<string.h>
 int main(){
 char ch[30];
 printf("Enter Your Namen");
 gets(ch);
 printf("You Entered :%sn",ch);
 printf("%dn",strlen(ch));
 printf("%d",strcmp("O","N"));
 printf("%sn",strlwr(ch));
 printf("%sn",strrev(ch));
 printf("%sn",strupr(ch));
 printf("%sn",strcat(ch,"Hello"));
 return 0;
 }
RTS tech. 61

62. String Pointer
 #include<stdio.h>
 #include<string.h>
 int main(){
 char s[20]="RTS Tech";
 int *p=s;
 printf("%sn",p);
 printf("%sn",s);
 }
RTS tech. 62

63. Math
 #include<stdio.h>
 #include<math.h>
 int main(){
 printf("%fn",pow(2,2));
 printf("%fn",sqrt(4));
 printf("%fn",cbrt(27));
 printf("%dn",abs(-9.0));
 printf("%fn",exp(2));
 printf("%fn",fabs(-4.8));
 return 0;
 }
RTS tech. 63

64. Random Numbers
 #include<stdio.h>
 #include<stdlib.h>
 #include<time.h>
 int main(){
 //to get new random numbers every time
 srand(time(0));
 int random=rand();
 printf("Random number %d",random);
 return 0;
 }
RTS tech. 64

65. Random No in Range
 #include<stdio.h>
 #include<stdlib.h>
 #include<time.h>
 int main(){
 //to get new random numbers every time
 srand(time(0));
 int max=10, min=4;
 int random=(rand()%(max-min))+min;
 printf("Random number %d",random);
 return 0;
 }
RTS tech. 65

66. Pointers
 ‘*’ symbol is used as pointer operator.
 It is called value at address operator.
 It gives the value stored at particular address.
 It is also known as indirection operator
RTS tech. 66

67. Pointer Notation:
 Int j=10;
RTS tech. 67
j
10
10101
Memory Location name
value
Location address

68. Pointers(cont.)
 #include<stdio.h>
 int main(){
 int j=10;
 int *b;
 b=&j;
 printf("j=%dn",j);
 printf("b=%dn",b);
 printf("*b=%dn",*b);
 printf("&j=%dn",&j);
 return 0;
 }
RTS tech. 68
j
10
65524
b
65524
60500

69. Double Pointer
 #include<stdio.h>
 int main(){
 int i=10,*a,**b;
 a=&I,b=&a;
 printf(“i=%dn",i);
 printf("a=%dn",a);
 printf("b=%dn",b);
 printf("&i=%un",&i);
 printf("&a=%un",&a);
 printf("&b=%un",&b);
 printf("*a=%dn",*a);
 printf("**b=%dn",**b);
 return 0;
 }
RTS tech. 69
i
10
65524
a
65524
60500
b
60500
60504

70. Function
 Function is a block of statements to perform specific
task.
RTS tech. 70
Types of Functions
Library Functions
User Defined
Functions
printf()
scanf()
sum()
display()

71. Function With return type
 #include<stdio.h>
 int sum(int , int);
 int main(){
 int i=2, j=4;
 int result=sum(i,j);
 printf("%dn",result);
 return 0;
 }
 int sum(int a, int b){
 return a+b;
 }
RTS tech. 71
Function prototype
Function call
Function’s Definition

72. Function without return type
 #include<stdio.h>
 void sum(int , int);
 int main(){
 int i=2, j=4;
 sum(i,j);
 return 0;
 }
 void sum(int a, int b){
 printf("%dn",a+b);
 return;
 }
RTS tech. 72

73. Call by value
 #include<stdio.h>
 void swap(int, int);
 int main(){
 int x=12, y=10;
 swap(x,y);
 printf("x=%d, y=%dn",x,y);
 return 0;
 }
 void swap(int a, int b){
 int t=0;
 t=a;
 a=b;
 b=t;
 printf("a=%d, b=%dn",a,b);
 }
RTS tech. 73

74. Call by reference
 #include<stdio.h>
 void swap(int *, int *);
 int main(){
 int x=12, y=10;
 swap(&x,&y);
 printf("x=%d, y=%dn",x,y);
 return 0;
 }
 void swap(int *a, int *b){
 int t=0;
 t=*a;
 *a=*b;
 *b=t;
 }
RTS tech. 74

75. Recursion
 A function calls itself is known as recursive function.
 We have to define the termination condition for this
type of functions.
RTS tech. 75

76. Recursive Function
 #include<stdio.h>
 int fact(int);
 int fact(int n){
 if(n==1 || n==0){
 return 1;
 }else{
 return n*fact(n-1);
 }
 }
 int main(){
 printf("%dn",fact(5));
 return 0;
 }
RTS tech. 76

77. Array
 Array is used to store multiple elements of similar
type.
 Array stores all the elements in a continuous memory
locations.
 We can access elements of an array using index.
 Array index start with 0.
RTS tech. 77

78. One Dimensional Array
 int i[]={1,2,3,4,5};
 OR
 Array declaration
 int i[5];
 Assign value to an Array
 i[0]=2;
 Access Element from an array
 int Val=i[0];
RTS tech. 78
1
2
3
4
5
0
1
2
3
4

79. Multidimensional Array
RTS tech. 79
int a[][]={{1,0,1},{3,4,1}}
OR
int a[][3]={{1,0,1},{3,4,1}}
OR
int a[2][3]={{1,0,1},{3,4,1}}
1D Array 2D Array 3D Array
int a[]={3,2}
OR
int a[2];
int a[2][3][3];

80. Two Dimensional Array
RTS tech. 80

81. Two Dimensional Array
 #include<stdio.h>
 int main(){
 int arr[][3]={{1,2,3},{3,4,5},{6,7,8}}
;
 for(int i=0; i<3;i++){
 for(int j=0; j<3;j++){
 printf("%d",arr[i][j]);
 }
 printf("n");
 }
 return 0;
 }
RTS tech. 81

82. Three Dimensional Array
 #include <stdio.h>
 int main()
 { int a[2][5][5];
 for (int i = 0; i < 2; i++){
 for (int j = 0; j < 5; j++){
 for (int k = 0; k < 5; k++){
 a[i][j][k]=i+j+k;
 printf("%d", a[i][j][k]);
 }
 printf("n");
 }
 printf("n");
 }return 0;
 }
RTS tech. 82

83. Pointer to an array
RTS tech. 83

84. Pointer to array(cont.)
 #include<stdio.h>
 int main(){
 int a[]={1,2,3,4,5,6,7};
 int *p;
 p=a;
 printf("%un",a);
 printf("%un",p);
 for(int i=0; i<7;i++){
 printf("%dn",*(p+i));
 }//OR
 for(int i=0; i<7;i++){
 printf("%dn",a[i]);
 }
 return 0;
 }
RTS tech. 84

85. Structure
 It is a derived Data type in c.
 Structure is used to store different types of values under a
single name.
 struct keyword is used to create a structure in c.
 Syntax:
 struct structure_name{
 data_type var1;
 data_type var2;
 ...
 };
RTS tech. 85

86. Define structure variables
 We can define structure variable in two manner:
 Using struct keyword in main method.
 int main(){
 struct structure_name var1,var2;
 Define the variables at the time of defining structure.
 struct structure_name{
 data_type var1;
 data_type var2;
 }var1,var2;
RTS tech. 86

87. Structure example
 #include <stdio.h>
 #include <string.h>
 struct Person{
 char name[50];
 int age;
 char address[50];
 }p1;
 int main()
 { //struct Person p1;
 //Person's Info
 strcpy(p1.name, "Ram");
 strcpy(p1.address, "Indore");
 p1.age = 20;

//print details of the person
 printf("Name: %sn", p1.name);
 printf("Age: %dn", p1.age);
 printf("Address: %sn", p1.address);
 return 0;
 }
RTS tech. 87

88. Nested Structure
 #include <stdio.h>
 struct Person{
 char name[50];
 int age;};
 struct Student{
 int rollno;
 struct Person p;};
 int main(){
 struct Student std;
 printf("Enter Name , Age and RollNo of the studentn");
 scanf("%s %d %d", &std.p.name,&std.p.age, &std.rollno);
 printf("Name =%s , age=%d, rollno=%dn", std.p.name, st
d.p.age, std.rollno);
 return 0;
 }
RTS tech. 88

89. typedef
 It is a keyword in c to define the aliases to existing
names.
 We can give a name to existing data types and
structures etc.
 Syntax:
 typedef existing_name new_name;
RTS tech. 89

90. Typedef example
 #include <stdio.h>
 int main()
 {
 typedef unsigned int data;
 data a, b;
 printf("Enter the value of a and bn")
;
 scanf("%d %d", &a, &b);
 printf("a=%d, b=%dn", a, b);
 return 0;
 }
RTS tech. 90

91. Union
 It is a user defined data type.
 union keyword is used to define the union in c.
 Unlike structure union shares the same memory location.
 Union allocates memory of the data variables one at a
time.
 The size of the union will be the largest element in the
union.
 It is used to group the items.
RTS tech. 91

92. Union
 #include <stdio.h>
 union Person{
 char name[20];
 int age;
 char address[50];
 } p1;
 int main(){
 printf("Enter the namen");
 scanf("%s", &p1.name);
 printf("Name=%sn", p1.name);
 printf("Enter the addressn");
 scanf("%s", &p1.address);
 printf("Name=%sn", p1.address);
 printf("Enter the agen");
 scanf("%d", &p1.age);
 printf("age=%dn", p1.age);
 printf("%dn", sizeof(p1));
 return 0;}
RTS tech. 92

93. Preprocessor
 It pre-processed our program before compilation.
 It is also known as micro preprocessor.
 All preprocessor directives starts with ‘#’.
 Preprocessor directives can be placed anywhere in the program.
 Preprocessor’s List:
RTS tech. 93
#include #define #undef
#if #endif #else
#elif #ifdef #ifndef
#error #pragma

94. Define Macros
 Macros is a code segment which is replaced by its value.
 It makes program readable and Faster.
 Types:
 Object-Based (without argument)
 Function Based(with argument)
 Macro has 2 parts macro template and macro expansion.
 #define PI 3.14
RTS tech. 94
Macro template Macro expansion

95. Object Based
 #include <stdio.h>
 #define PI 3.14
 int main()
 {
 printf("EnterRadius of the Circlen");
 float radius;
 scanf("%f", &radius);
 float area = pi * radius * radius;
 printf("Area: %fn", area);
 return 0;
 }
RTS tech. 95

96. Function Based
 #include <stdio.h>
 #define PI 3.14
 #define AREA(r) (PI*r*r)
 int main()
 {
 printf("Enter Radius of the Circlen");
 float radius;
 scanf("%f", &radius);
 float area = AREA(radius);
 printf("Area: %fn", area);
 return 0;
 }
RTS tech. 96

97. Predefined Macros
 #include<stdio.h>
 int main(){
 printf("File :%sn", __FILE__ );
 printf("Date :%sn", __DATE__ );
 printf("Time :%sn", __TIME__ );
 printf("Line :%dn", __LINE__ );
 printf("STDC :%dn", __STDC__ );
 return 0;
 }
RTS tech. 97

98. Preprocessor Directives
Directives Uses
#include To include file either predefine or user define
#define To define Macros
#undef To undefine macros which is define by #define
#ifdef It checks and execute the macro which is define by
#define if not then #else is execute.
#if It checks the condition and execute the if block
#elif It It checks the condition and execute the elif block
#endif It is end of the #if
#ifndef It checks and execute the macro if not define by #define
otherwise #else is execute.
#error It indicates error
#pragma It provides additional information to the compiler.
RTS tech. 98

99. Command Line Arguments
 #include<stdio.h>
 int main(int argc, char *argv[]){
 printf("Total argument %dn",a);
 printf("Fle name:%sn",args[0]);
 printf("Hello %sn",args[1]);
 printf("%sn",args[2]);
 return 0;
 }
RTS tech. 99

100. File IO
 We can perform operation on file in C.
 WE can perform following operation on File:
 Creating a new file
 Opening a File
 Deleting a file
 Update the file
 Write to a file
 Read data from file
RTS tech. 100

101. Types of Memory
.NO Volatile Memory Non-Volatile Memory
1.
Data is lost as it is powered-
off.
Data remains stored even if it is
powered-off.
2. Contents is stored temporarily. Contents stored permanently.
3. It is faster. It is slower.
4. For ex. RAM. For ex. ROM
RTS tech. 101

102. File Modes
 r: to read existing file
 w: to write into a file if
exist otherwise creates
new
 a: to update a existing file
otherwise creates new
 rb: to read a binary file
 wb: to write a binary file
 ab: to append the data to a
binary.
 r+: for read write both
 w+: for read write both
 a+: for read write both, but
writing starts with end of
file.
 r+b(rb+): read write binary
file
 w+b(wb+): read write binary
file
 a+b(ab+): read write binary
file
RTS tech. 102

103. Writing to a Text File
 #include<stdio.h>
 int main(){
 FILE *file;
 file = fopen("test.txt","w");
 for (int i = 0; i <10; i++)
 {
 fprintf(file,"%s %dn","Line No",i);
 }
 printf("Data saved to file");
 fclose(file);
 return 0;
 }
RTS tech. 103

104. Reading from a Text File
 #include <stdio.h>
 int main(){
 FILE *fp;
 char buff[255];//creating char array to
store data of file
 fp = fopen("test.txt", "r");
 while(fscanf(fp, "%s", buff)!=EOF){
 printf("%s ", buff );
 }
 fclose(fp);
 return 0;
 }
RTS tech. 104

105. Write char by char
 #include <stdio.h>
 int main(){
 FILE *file;
 file = fopen("Test.txt", "w");
 for(int i=65; i<90; i++){
 fputc((char)i, file);
 }
 fclose(file);
 printf("Data saved");
 return 0;
 }
RTS tech. 105

106. Read Char by char
 #include <stdio.h>
 int main(){
 FILE *file;
 file = fopen("Test.txt", "r");
 char c=fgetc(file);
 while(c!=EOF){
 printf("%c",c);
 c=fgetc(file);
 }
 fclose(file);
 return 0;
 }
RTS tech. 106

107. Copy Binary File
 #include<stdio.h>
 #include<stdlib.h>
 int main(){
 FILE *from, *to;
 from = fopen(“Image.jpg","rb");
 to=fopen(“Copy.jpg","wb");
 int ch;
 ch=fgetc(from);
 while(ch != -1) {
 fputc(ch,to);
 ch=fgetc(from);
 }
 fclose(from);
 fclose(to);
return 0;
 }
RTS tech. 107

108. File Operation
RTS tech. 108
Operation Description
fopen() to open a new or existing file
fclose() to close a file()
fprintf() To write data
fscanf() To read data
fputc() To write single character
fgetc() To read single character
fputw() To write Integer
fgetw() To read Integer
fputs() To write data
fgets() To read data
rewind To set file pointer to the beginning.
seek() To set file pointer to the given position
ftell() Returns file pointer location

109. Enum
 It is User define data type.
 Enum keyword is used to create enum type.
 We can create constants by enum.
 It consists of integer values, and it provides meaningful
names to these values.
 We can define a enum type without a name
RTS tech. 109

110. Enum type
 enum Weekday{SUNDAY,MONDAY,TUESDAY,WEDN
ESDAY,THURSDAY,FRIDAY,SATURDAY};
 #include<stdio.h>
 int main(){
 enum Weekday day;
 day=SATURDAY;
 printf("Weekday %d",day);
 return 0;
 }
RTS tech. 110

111. Dynamic memory allocation
 We can assign memory at runtime.
 We need <stdlib.h> header file which contains 4
dynamic memory allocation function.
 malloc(): allocate single block of requested memory.
 calloc(): allocate multiple block of requested memory.
 Free(): frees dynamically allocated memory
 realloc(): reallocate memory occupied by malloc()
and calloc().
RTS tech. 111

112. malloc
 Defined in <stdlib.h> header file.
 Allocates requested memory.
 If allocation succeed returns pointer to the 1st byte else
return NULL or Void
 To avoid memory leak use free() to deallocate pointer.
 Syntax:
 void* malloc(size_t size);
RTS tech. 112

113. Implementation of malloc()
 #include <stdio.h>
 #include <stdlib.h>
 int main(){
 int *p1;
 p1 = malloc(sizeof(int[4]));
 if (p1){
 for (int i = 0; i < 4; i++){
 p1[i] = 2 * i + 1;
 }
 }for (int i = 0; i < 4; i++){
 printf("p1[%d]==%dn", i, p1[i]);
 }
 free(p1);
 return 0;
 }
RTS tech. 113

114. calloc()
 Defined in <stdlib.h> header file.
 Allocates memory according to number of objects.
 Initializes all bytes in the allocated storage to zero.
 If succeed returns pointer on failure return null pointer.
 Syntax:
 void* calloc( size_t num, size_t size
);
RTS tech. 114

115. Implementation of calloc()
 #include <stdio.h>
 #include <stdlib.h>
 int main(int argc, char *argv[]){
 // int *p1 = calloc(4, sizeof(int)); // allocate and zero out an
array of 4 int
 int *p1 = calloc(1, sizeof(int[4])); // same, naming the array typ
e directly
 // int *p3 = calloc(4, sizeof *p3); // same, without repeating
the type name
 if (p1) {
 for (int i = 0; i < 4; i++) {
 p1[i] = 2 * i + 1;
 }
 }for (int i = 0; i < 4; i++){
 printf("p1[%d]==%dn", i, p1[i]);
 }free(p1);
 return 0;
 }
RTS tech. 115

116. Disclaimer
 This is a educational Presentation to make
programming easier.
 We have used images of different URLs to make
presentation better.
 We respect the work of the owners of the URLs.
116
RTS tech.

117. Thank You!
RTS tech. 117
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