Module 1 - Introduction to C Programming.pptm (1).pdf

PRPEARED BY: PROF. NEHA HARDE ©
C PROGRAMMING
Module 1
Introduction to C Programming
Course Outcome (CO1):
Understand the basic syntax and semantics of C.

 What is Computer ?
 Characteristics of computer
 Benefits of computer
 Computer Components
 Input Devices
 Output Devices
 Central Processing Unit
 Memory Unit
Introduction to Components
of a computer system

WHAT IS COMPUTER ?
A computer is a programmable electronic
device that accepts raw data as input and
processes it with a set of instructions (a
program) to produce the result as output
The father of the
computer:
Charles Babbage

WHAT IS COMPUTER ?

CHARACTERISTICS OF COMPUTER
Speed Memory Accuracy Diligence Versatile
Multitask
ing

BENEFITS OF COMPUTER
Storage
Increases
Productivity
Connects
to the
Internet
Improves
ability
Provides
an
entertainm
ent
Organizes
data and
information

COMPUTER COMPONENTS

COMPUTER COMPONENTS
 Input is any data or instruction given to the computer
 Input device enables the user to send data, information, or control signals
to a computer
 The prime purpose of input devices are to translate data and information
from human-readable format into electrical impulses
1. Input Devices

INPUT DEVICES
 Keyboard is a basic input device that is
used to enter data into a computer or any
other electronic device by pressing keys
 Mouse is a pointing hand-held input
device which is used to move cursor or
pointer across the screen

 Scanner scans the picture or a document
converts it into a digital format and is
displayed on the screen as an output
 Joystick is a pointing input device like a
mouse and movement of stick controls the
cursor or pointer on the screen
INPUT DEVICES

 Light pen is like a pen. The tip of the light
pen contains a light-sensitive detector that
enables the user to point to or select objects
on the display screen
 Microphone is used to input the sound to
presentations and with webcams for video
conferencing
INPUT DEVICES

COMPUTER COMPONENTS
 The output device displays the result of the processing of raw data that is
entered in the computer through an input device
 It is used to bring out the information from the computer
2. Output Devices

 Monitor is the display unit or screen of the
computer that displays the processed data or
information as text, images, audio or video
 Printer is a device that prints text, images or
any information on paper producing hard
copy of the information
OUTPUT DEVICES

 A projector is an output device that enables
the user to project the output onto a large
surface such as a big screen or wall
 Speaker is an output device connected to a
computer's sound card that outputs sounds
generated by the computer
OUTPUT DEVICES

COMPUTER COMPONENTS
 Brain of the computer system
 It receives instructions from both the hardware and
active software and produces output accordingly
3. Central Processing Unit

CENTRAL PROCESSING UNIT (CPU)
 Control Unit is used to control the entire working
of a computer system and it controls the transfer of
data between memory and input/output devices or
I/O devices
 Arithmetic and Logic Unit is designed to
perform all the basic arithmetic operations and
logical operations

COMPUTER COMPONENTS
 Memory unit is used to retain the program instruction and data for processing
 Two types of memory:
Primary Memory
Secondary Memory
4. Memory Unit

MEMORY UNIT
 Main memory of the computer
 Directly accessed by the CPU
 Volatile
 Faster access
 Semiconductor Memory - Expensive
 Less storage capacity
Primary Memory

Primary Memory
MEMORY UNIT

 External Memory
 High storage capacity
 Permanent storage
 Non volatile
 Slower access
 Magnetic or optical memory - Less Expensive
Secondary Memory
MEMORY UNIT

MEMORY UNIT

 What is Algorithm ?
 Characteristics of algorithm
 How to write an algorithm ?
 Flowchart
 Flowchart Symbols
 How to draw a flowchart ?
Introduction to Algorithm
and Flowchart

WHAT IS ALGORITHM
An algorithm can be defined as a finite set of steps, which has to be followed
while carrying out a particular problem
An algorithm is a distinct computational procedure that takes input as a set of
values and results in the output as a set of values by solving the problem

CHARACTERISTICS OF ALGORITHM
• Well defined zero or more inputs
Input
• Generate at least one output
Output
• Each Instruction should be clear
Unambiguous
• Algorithm should terminate after executing
finite no. of instructions
Finiteness
• Every instruction should be fundamental to be
carried out, in principle
Effectiveness

HOW TO WRITE AN ALGORITHM
Step 1: Start
Step 2: Read values num1 and num2.
Step 3: Add num1 and num2 and assign the result to sum.
sum←num1+num2
Step4: Display sum
Step 5: Stop
Example: Add two numbers

HOW TO WRITE AN ALGORITHM
Step 1: Start
Step 2: Read variables a, b and c.
Step 3: If a > b
If a > c
Display a is the largest number.
Else
Display c is the largest number.
Else
If b > c
Display b is the largest number.
Else
Display c is the greatest number.
Step 4: Stop
Example: Find the largest number among three numbers

FLOWCHART
A flowchart is a visual representation of the sequence
of steps and decisions needed to perform a process
A flowchart is a powerful business tool - With proper
design and construction, it communicates the steps in
a process very effectively and efficiently.

FLOWCHART SYMBOLS

HOW TO DRAW A FLOWCHART
Example: Add two numbers
Step 1: Start
Step 2: Read values num1 and num2.
Step 3: Add num1 and num2 and assign the result to sum.
sum←num1+num2
Step 5: Display sum
Step 5: Stop

HOW TO DRAW A FLOWCHART
Example: Find the largest number among three numbers
Start
Input a, b, c
Is
a>b ?
Is a>c
?
Yes
Is b>c
?
No
Print a is the
largest number
Yes
Print c is the
largest number
No
No
Print b is the
largest number
Yes
End

 What is Programming Language ?
 Types of Programming Languages
 What is Compiler ?
 What is Interpreter ?
 Compiler Vs Interpreter
 C Programming Language
 Features of C
 Applications of C
 C Program Structure
 Compilation Process
Introduction to C Programming

WHAT IS PROGRAMMING LANGUAGE
A programming language is a computer language that is used
by programmers (developers) to communicate with computers

TYPES OF PROGRAMMING LANGUAGES
Low Level Programming Language
High Level Programming Language
Middle Level Programming Language
 Machine Dependent
 Runs without the need of compiler and interpreter
 Example: 0 1 (Binary)
 User friendly
 Used to develop applications, websites
 Requires compiler and interpreter
 Example: Python, C, C++, Java
 Related to both high level and Machine level
languages
 Requires Assembler
 Example: Assembly Language

TYPES OF PROGRAMMING LANGUAGES

WHAT IS COMPILER ?
A compiler is a computer program that transforms code written
in a high-level programming language into the machine code

WHAT IS INTERPRETER ?
An interpreter is a computer program, which coverts each
high-level program statement into the machine code.

COMPILER VS INTERPRETER

C PROGRAMMING LANGUAGE
 C is a general-purpose, structured programming language
that is extremely popular, simple, and flexible to use
 Developed in 1972 by Dennis Ritchie at bell laboratories of
AT&T, located in the U.S.A.
 Mother of Programming Languages - C programming is
considered as the base for other programming languages

FEATURES OF C

APPLICATIONS OF C

C PROGRAM STRUCTURE
/* C program to Print Hello World */
#include<stdio.h>
#define MAX 10
int a = 20;
int main()
{
printf(“Hello World”);
printf(“a = %d”, a);
return 0;
}

COMPILATION PROCESS

 Constants
 Keywords
 Identifiers
 Variables
 Types of Variables
 Data Types
 Operators
 Unary Operators
 Binary Operators
 Ternary Operators
 Operator Precedence
 Operator Associativity
 Input and Output Functions
 Format Specifiers
 Formatted I/O Functions
 Unformatted I/O Functions
Basics of C

CONSTANTS IN C
 Constants or literals are like variables, but their values are
fixed
 Once defined, value of the constant cannot be changed

CONSTANTS IN C
1. Numeric Constants
Integer Constants: Sequence of digits
• Decimal Integer
Example:
12 250 -4500 0
• Octal Integer
Example:
05 0632
• Hexadecimal Integer
Example:
0X6A 0x79BD 0X346
Rules for Constructing Integer Constants:
 An Integer constant must have at least one
digit
 It can be either positive or negative
 No commas or blanks or special symbols are
allowed
 Allowable range is -32768 to 32767

CONSTANTS IN C
1. Numeric Constants
Real Constants: (Floating point constants)
Numbers having fractional part
Example:
34.89 -22.1845 +0.76
Exponential Representation of Real Constants:
Example:
6.78e3 -0.45E-4
Rules for Constructing Real Constants:
 An real constant must have at least one digit
and decimal point
 It can be either positive or negative
 No commas or blanks or special symbols are
allowed
Mantissa Exponent

CONSTANTS IN C
2. Character Constants
Single Character Constants:
Single character or Single Digit or Single Special
Symbol enclosed within single inverted commas
Example:
‘A’ ‘m’ ‘8’ ‘@’
Note: 8 ≠ ‘8’
Rules for Constructing Single Character Constants:
 Length of character constant can be 1 character
 Character constant should be in single inverted
commas

CONSTANTS IN C
String Constants:
Sequence of characters enclosed within double quotes
Example:
“college” “m” “a8bn”
Note:
1. ‘a’ ≠ “a”
2. Compiler will add ‘0’ (null character at the end of
the string
Rules for Constructing String Constants:
 String constants should be enclosed within
double quotes
 String constants can be of any length
 String constant ends with a null character
assigned to it by the compiler

CONSTANTS IN C
Backslash Character Constants: (Escape Sequences)
Backslash characters have a specific meaning which is
known to the compiler

CONSTANTS IN C
Defining Constant
1. Using const Keyword
Syntax:
const data_type constant_name = value;
Example:
const int A = 10;
2. Using #define pre-processor
Syntax:
#define const_name value
Example:
#define PI 3.14
Two ways to define constants

KEYWORDS IN C
Keywords are the reserved words having specific
meaning defined to the compiler
 32 Keywords in C
 Keywords cannot be used as a variable names

KEYWORDS IN C

IDENTIFIERS IN C
Identifiers represent the name in the C program; Like names of
variables, functions, arrays, structures, unions, labels
Note:
C is a case
sensitive language
Sum ≠ sum

IDENTIFIERS IN C
Rules for Constructing String Constants:
 An identifier can only have alphanumeric characters (a-z , A-Z , 0-9) (i.e. letters & digits)
and underscore( _ ) symbol.
 Identifier names must be unique
 The first character must be an alphabet or underscore.
 You cannot use a keyword as identifiers.
 Only the first thirty-one (31) characters are significant.
 It must not contain white spaces.
 Identifiers are case-sensitive.

VARIABLES IN C
A variable is a name given to the memory location where
data is stored depending upon the type of the variable
Variable Declaration:
Syntax:
data_type variable_name;
Example:
int choice;
char ans;
10 20
5 ‘a’
n1
ch
n3
n2
100
200
140
104

VARIABLES IN C
Variable Initialization:
Variable initialization means assigning some value to that variable
Example:
int ch;
ch = 10;
OR
Variable Declaration and initialization on the same line
int ch = 10;

TYPES OF VARIABLES

TYPES OF VARIABLES
1. Local Variables
 A variable that is declared inside the function or block is called a local variable
 Scope: Lies within the function or block of code
 Life: Stay in the memory till the end of the program
 Example:
void fun1()
{
int lv = 20;
printf(“value = %d”, lv);
}

TYPES OF VARIABLES
2. Global Variables
 A variable that is declared outside the function or block is called a global variable
 Value of global variable can be changed by any function
 Scope: Available to all functions
 Life: Stay in the memory till the end of the program
 Example:
int gv = 10;
void fun1()
{
int lv = 20;
printf(“value of lv = %d n value of gv= %d ”, lv, gv);
}

TYPES OF VARIABLES
3. Static Variables
 A variable declared with static keyword which retains its value within the function calls is
called as static variable
 Cannot be initialized again
 Scope: Local to the function or block
 Life: Value retains within the function calls
 Example:
static int a = 11;

TYPES OF VARIABLES
4. Automatic Variables
 All variables in C that are declared inside the block, are automatic variables by default
 Explicit declaration using auto keyword
 Scope: Local to the function or block
 Life: Till the end of the block
 Example:
void fun1()
{
int a = 10; // Automatic
auto int b = 20;
}

TYPES OF VARIABLES
5. External Variables
 We can share a variable in multiple C source files by using an external variable
 extern keyword is used
 Scope: Global in other files too
 Life: Till the end of the program
 Example:
extern int a;
Pro1.c
extern int a = 10;
Pro2.c
#include<stdio.h>
#include “pro1.h”

DATATYPES IN C
Data types refer to the characteristics of data stored into a variable
Data type helps you find Size, range and type of value
C Data Types are used to:
 Identify the type of a variable when it declared
 Identify the type of the return value of a function
 Identify the type of a parameter expected by a function
10 20
5 ‘a’
n1
ch
n3
n2
100
200
140
104

DATATYPES IN C

DATATYPES IN C
Primitive Data Types
2𝑏𝑖𝑡 − 1

DATATYPES IN C

DATATYPES IN C
2𝑏𝑖𝑡
− 1

OPERATORS IN C
 C operators are symbols that are used to perform mathematical or logical manipulation
 The C programming language is rich with built-in operators
 Operators take part in a program for manipulating data and variables and form a part of
the mathematical or logical expressions
Mathematical Expression:

OPERATORS IN C
Operators are symbols or a set of symbols that change or assign values, combine
values, or check or verify values in your code
Types of Operators:
1. Unary Operator
2. Binary Operator
3. Ternary Operator

UNARY OPERATORS
Unary Operators are the operators which require single operand to perform any action
1. Sizeof
2. Unary minus
3. Logical NOT
4. Increment
5. Decrement
6. & (Addrss of)
7. * (Value of)

UNARY OPERATORS
1. sizeof: return the size of an operand in bytes (prefix Operator)
Example: sizeof(operand)
2. unary minus: it negates a value (Prefix Operator)
Example: a = -10;
b = -a;
3. Logical NOT: The logical NOT operator inverts the value of a Boolean variable (Prefix Operator)
Example: c = True
a = !c;

UNARY OPERATORS
4. Increment: (Prefix and Postfix)
Increment : ++ (increases a numeric value by 1) a = a + 1
a) Post Increment:
Example: a++
b) Pre Increment:
Example: ++a

UNARY OPERATORS
5. Decrement: (Postfix and Prefix)
Decrement: -- (decreases a numeric value by 1) a = a – 1
a) Post Decrement:
Example: a--
b) Pre Decrement:
Example: --a

UNARY OPERATORS
6. & (Address of): Returns the address of a variable (Prefix Operator)
Example: &a
7. * (Value of): Returns value stored at the address (Works with pointers)
Example: *a

BINARY OPERATORS
Binary Operators are the operators which require two operands to perform any action
1. Arithmetic
2. Relational
3. Logical
4. Bitwise
5. Assignment

BINARY OPERATORS
1. Arithmetic Operators: used to perform arithmetic/mathematical operations
Consider a = 20 and b = 10

BINARY OPERATORS
2. Relational Operators: used to compare two values
Consider
a = 5
b = 10

BINARY OPERATORS
3. Logical Operators: used to test more than one condition
Consider x = 10 and y = 20

BINARY OPERATORS
4. Bitwise Operators: used to perform bit level operations

BINARY OPERATORS
5. Assignment Operators: used for assigning a value to a variable

TERNARY OPERATOR
 The ternary operator is also called as “Conditional Operator”
 Syntax:
Condition ? expression1 : expression2
Example:
x = a > b ? a+10 : b;
 A ternary operator is a short form of if-else

OPERATOR PRECEDENCE
The precedence of operators determines which operator is
executed first if there is more than one operator in an expression
Two ways to solve
= (10+20)*30
=900
=10+(20*30)
=610

OPERATOR PRECEDENCE
Problem:
 To generate machine level instructions that could properly evaluate arithmetic expression
Understand the meaning of an expression:
Decide the order in which the operations are to be carried out
 Fix the order of evaluation, assign each operator a priority
X = a / b * c - d
X = (a / b * c) - d
X = (a / b)* (c – d)

OPERATOR PRECEDENCE
Understand the meaning of an expression:
 Evaluate the expression from right to left or left to right (This order of
evaluation, from left to right or right to left, is called associativity)
A+ B - C
A + (B – C)
(A + B) - C
Operators Precedence and Associativity are two characteristics of operators that
determine the evaluation order of sub-expressions in absence of brackets

OPERATOR PRECEDENCE

OPERATOR ASSOCIATIVITY

PRACTICE QUESTION
What is the output of the code:
#include<stdio.h>
int main()
{
int a = 15;
printf("n %d %d %d %d", a++, --a, a--, ++a);
// Updated
//Printed
printf("n %d %d %d", a++, a--, --a);
return 0;
}

INPUT OUTPUT FUNCTIONS

FORMAT SPECIFIERS

FORMATED I/O FUNCTIONS
printf()
Syntax:
printf(“Format string”, List of variables);
Example:
printf(“n Value of a = %d”, a);
Format string can contain:
 Characters to print
 Conversion specification (%)
 Escape Sequences ()

FORMATED I/O FUNCTIONS
scanf()
Syntax:
scanf(“Format string”, List of addresses of variables);
Example:
scanf(“%d %f %c”, &a, &b, &c);
Format string can contain:
 Conversion specification (%)

UNFORMATED I/O FUNCTIONS
Unformatted Input functions
getch():
getch() is used to get a character from the
console but does not echo to the screen
Library: conio.h
Example:
char ch;
ch = getch();
getche():
getche() is used to get a character from the
console and echo to the screen
Library: conio.h
Example:
char ch;
ch = getche();

Unformatted Input functions
getchar():
getchar() is used to get or read the input
(i.e a single character) at runtime
Library: stdio.h
Example:
char ch;
ch = getchar();
gets():
gets() accepts single or multiple characters
of string including spaces
Library: stdio.h
Example :
char ch[10];
gets(ch);

Unformatted Output functions
putch():
putch displays any alphanumeric characters to
the standard output device
Syntax:
putch(variable_name);
Example:
char ch = 'a';
putch(ch);
putchar():
putchar() displays any alphanumeric characters
to the standard output device
Syntax:
putchar(variable_name);
Example:
char ch = 'a';
putchar(ch);

Unformatted Output functions
puts():
puts() displays single or multiple characters of string including spaces to the
standard output device
Syntax:
puts(variable_name);
Example:
char ch[10]="Example";
puts(ch);

Module 1 - Introduction to C Programming.pptm (1).pdf

More Related Content

Similar to Module 1 - Introduction to C Programming.pptm (1).pdf

Recently uploaded

Module 1 - Introduction to C Programming.pptm (1).pdf