1. C Programming Mr. KAJAL MAJI ASSISTANT PROFESSOR DEPARTMENT OF PHYSICS
B.B. COLLEGE ASANSOL

2. Dept. of Physics, B.B.College Asansol
What is C Program?
A sequence of logically related instructions that enables the computer to perform a complete task is known as a program.
A computer can only understand instructions written in binary form i.e. 0 and 1.
A program written in binary form is referred to as machine language.
Dept. of Physics, B.B.College Asansol

3. Dept. of Physics, B.B.College Asansol
Two types of language are used
1. Low level language
2. High level language
Low level language are machine and assembly languages.
High level language are FORTRAN, COBOL etc.
Dept. of Physics, B.B.College Asansol

4. Dept. of Physics, B.B.College Asansol
What is Compiler?
A high level language is translated into machine language by using a program in the memory.
A computer program written in high level language is known as source program.
This program when translated into machine language is called an object program.
Dept. of Physics, B.B.College Asansol

5. Character, Identifiers and Keywords
Characters: A to Z, lowercase letters a to z. The digit 0 t0 9.
Special characters: ; etc.
Combinations characters \b,\n, \t, etc
Keywords: auto, char, else, for, float, goto, int, if, retrun, void, while, const.
Identifiers: gross, sum , name, area, name.
Dept. of Physics, B.B.College Asansol

6. Dept. of Physics, B.B.College Asansol
Variables
Variables refer the objects that can be stored in computer’s memory locations. Variables are named (identifiers).
Variables must be declared and initialized.
Variables can store data of various types. Some basic data types are
char characters (1/2 bytes)
int integers (2/4 bytes)
float rationals (4 bytes)
double rationals(8 bytes
Dept. of Physics, B.B.College Asansol

7. Dept. of Physics, B.B.College Asansol
Declaration
Declarations have form
type var1, var2, var3;
Merely announces the data type to be associated with a variable
Examples
char name;
int a,b;
float c,d;
Dept. of Physics, B.B.College Asansol

8. Dept. of Physics, B.B.College Asansol
Array
An array is a collective name of variables of the same data type.
The individual variable making up an array is called an element of the array.
Example:
roll[1], roll[1]……….roll[20]
Dept. of Physics, B.B.College Asansol

9. Operators and Expressions
An operator is a symbol that tells the computer to perform certain mathematical or logical manipulations of data variables.
There are five types of operators:
1. Arithmetic operators
2. Relational operators
3. logical operators
4. Assignment operators
5. Unary operators
Dept. of Physics, B.B.College Asansol

10. Dept. of Physics, B.B.College Asansol
Arithmetic operators
addition
subtraction
* multiplication
/ division
% percentage
Dept. of Physics, B.B.College Asansol

11. Dept. of Physics, B.B.College Asansol
Relational operators
a>b a greater than b
a>=b a greater than or equal to b
a< b a less than b
a<=b a less than or equal to b
a==b a equal to b
a ! =b a equal to b
Dept. of Physics, B.B.College Asansol

12. Dept. of Physics, B.B.College Asansol
logical operators
&& logical AND
‖ logical OR
! logical NOT
Dept. of Physics, B.B.College Asansol

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Assignment operators
x= x x+=3
x=x x-=3
x=x*(n+2) x*=n+2
x=x/ x/=3
x=x% x%=3
Dept. of Physics, B.B.College Asansol

14. Dept. of Physics, B.B.College Asansol
Unary operators
++x or x++ increments x by 1
-- x or x-- decrements x by 1
-x negates the value of x
Example;
x=4;
y= ++x;
y=5;
Dept. of Physics, B.B.College Asansol

15. Dept. of Physics, B.B.College Asansol
Library Functions
main (): Every c program must have function main() which may access (call) other function
thus main () is a calling function.
Input and output function:
get char: Input function
variable name= getchar ();
scanf : Input function
scanf(“control string”, argument1);
Dept. of Physics, B.B.College Asansol

16. Dept. of Physics, B.B.College Asansol
Example:
int x;
float y;
scanf(“%d,%f”,&x,&y);
putchar: output function.
putchar(ch);
printf: output function.
printf(“control string”, argument 1);
printf(“%d %f”,x,y);
Dept. of Physics, B.B.College Asansol

17. Dept. of Physics, B.B.College Asansol
If-else statement
It is used to carry out a logical test and then take one of two possible actions depending on the outcome of the test.
if (test expression)
statement 1
else
statement 2
Dept. of Physics, B.B.College Asansol

18. Dept. of Physics, B.B.College Asansol
Example:
y=x4 if x>2
= x+3 otherwise
C-program:
……………..
if (x>2)
y=pow(x,4);
else
y=x+3
………………
Dept. of Physics, B.B.College Asansol

19. Dept. of Physics, B.B.College Asansol
Looping
In C language looping cab be done by using while, do while and for statements
1. while loop:
while (test condition) {
body of the loop }
Dept. of Physics, B.B.College Asansol

20. Dept. of Physics, B.B.College Asansol
Example:
………
sum=0;
n=1;
while (n<=100) {
sum=sum+m;
n=n+1; }
Dept. of Physics, B.B.College Asansol

21. Dept. of Physics, B.B.College Asansol
2. Do while loop: do {
body of the loop }
while (test condition)
Example:
int num=0;
printf(“%d\n”,num);
++num;
while(num<=11)
Dept. of Physics, B.B.College Asansol

22. Dept. of Physics, B.B.College Asansol
3. for loop:
for( initialization; test condition; increment) {
body of the loop }
Example:
……….
for (i=0; i<4;i++)
printf(“%d”.i);
Dept. of Physics, B.B.College Asansol

23. Algorithm and Flowchart
To write a program for a particular problem one must fully understand the nature of the problem, the kind of data to be given as input, kind of outputs need and the constraints and conditions under which the program has to operate. Depending on these one has to decide a solution procedure.
Flowchart is a pictorial representation of an algorithm.
Dept. of Physics, B.B.College Asansol

24. Dept. of Physics, B.B.College Asansol
Example:
Let us consider the algorithm and flowchart for the problem of finding the larger of two numbers.
Algorithm:
Step 1 : Start the process by declaring two
variables a and b.
Step 2 : Give the inputs and store them in the
Step 3 : Check, if a>b. If the answer is ‘yes’, go to
step 4. Otherwise go to step 5.
Step 4 : Print “a is greater than b” and go to step 6.
Step 5 : Print “b is greater than a” and go to step 6.
Step 6 : Stop.
Dept. of Physics, B.B.College Asansol

25. Dept. of Physics, B.B.College Asansol
Flowchart:
Start
Declare
variables a,b
Input a,b and
store their values
Is a>b?
NO Yes
Print Print
b>a a>b
Stop Stop
Dept. of Physics, B.B.College Asansol

26. Example: Area of the Sphere
#include<stdio.h>
main() {
float r=5, Area;
Area= 4*3.41*r*r;
printf(“The area of the sphere is %f\n”,area); }
Dept. of Physics, B.B.College Asansol

27. Dept. of Physics, B.B.College Asansol
Example: Matrix
#include<stdio.h>
main() {
int a=1,i,j,m, n,mat[10][10];
printf("Enter the row numbers : \t");
scanf("%d",&m);
printf("Enter the columb numbers : \t");
scanf("%d",&n);
printf("Enter the elements of the matrix :\t");
for(i=0;i<m;i++)
for(j=0;j<n;j++)
scanf("%d",& mat[i][j]);
printf("The given matrix is: \n");
printf("%d\t",mat[i][j]);
printf("\n"); }
Dept. of Physics, B.B.College Asansol