tutorial

CHAPTER 4

Fri, 20 May 2011 12:22:32 +0100

(1) %d :- It is use for integer value
(1) %f :- It is use for float value

printf() has two syntax :-

(i) printf(" Messege ") :- It is use two print any text
(ii) printf("%d / %f",variable); :- Two print values of variable

/* Program to explain use of float */
main()
{
float a;
clrscr();
a=5/2;
printf("a=%f",a);
getch();
}

OUTPUT
a=2.0

In this program if we divide any integer value with another integer value than answer will be in decimal but it will not correct like above example.
To solve this problem one number should be float.

/* Program to explain use of float */
main()
{
float a;
clrscr();
a=5.0/2;
printf("a=%f",a);
getch();
}

OUTPUT
a=2.5

/* Program to find area of circle*/
main()
{
float a,r;
clrscr();
printf("Enter radius of circle ");
scanf("%f",&r);
a=3.141 * r * r;
printf("Area is %f",a);
getch();
}

OUTPUT
Enter radius of circle 2
Area is 8.564

QUESTION

Write a program to input principle,rate,time and calculate simple interest ?

CHAPTER 3

Fri, 20 May 2011 12:21:44 +0100

CHARACTER SET
The character set that can be used to form words, numbers and expressions are called character set.
Elements of character set :-
1.Letters --> A to Z , a to z
2.Digits --> 0 to 9
3. Special Characters --> +,-,*,/,:,;,(,),[,],{,},<,>,=,&,%,_,^,,,",',.,\,etc.
4.White spaces --> Newline,horizontal tab,carriage return,blank space.

IDENTIFIER

Identifier reverse to the name of variables,constants,functions and arrays.These are the user defined names end consist sequence of letters,digits and under score.

Rules for identifiers :

(i) It can contain letters,digits and underscore but the first character must
always be a letter.
(ii) No special character except underscore is allowed even space are not
allowed.
(iii) Both uppercase & lowercase characters are allowed but lowercase will be
treated as different from uppercase.
(iv) Keyword can not be used as identifier.

KEYWORD (RESERVED WORDS)

All keywords have fixed meaning and these meaning can not be changed. Keywords are predefined. They are 32 keywords in 'C' language.

Example : int,float,char,for,break,if,etc.
Keyword must be always written in lowercase.

VARIABLE

Variable is use to store a data value. The value of variable can be change during execution of program.

CONSTANT

Constant means fixed value that do not change during the execution of program.

CHAPTER 2

Fri, 20 May 2011 12:17:51 +0100

START PROGRAMMING
How to open C compiler:
1.Copy the C compiler file to the C drive.
2.Click START menu and select run option.
3.In run box type cmd command and click OK button.
4.Command prompt window will be open.
5.Type the following commands:
C:\Documents and settings\xp>cd\
C:\>cd turboc2
C:\turboc2>tc
FIRST PROGRAM :
Example 1

/*My first program*/
main()
{
clrscr(); /* This function clear screen */
printf("Good Afternoon"); /* This function prints message */

getch();
}

Output:-
Good Afternoon

printf(): Function is use to display a message on the screen.
getch(): This function is use to input a character from keyboard .
clrscr(): This function is use to clear the screen.

Example 2

/*My 2 program*/
main()
{
clrscr();
printf("Good");
printf("Afternoon");
getch();
}

Output:-
Good Afternoon

\n: It is use to change a line.

Example 3

/*My 3 program*/
main()
{
clrscr();
printf("Good");
printf("\nAfternoon");
getch();
}

Output:-
Good
Afternoon

Program 4

/*Program to print sum of two numbers*/
main()
{
int num1,num2,sum; /* Declaring numbers */
clrscr();
num1=10; /* Assigning values */
num2=20;
sum=num1+num2; /* Addition */
printf("Total is %d",sum);
getch();
}

Output:-
Total is 30

Program 5

/*Program to print sum of two numbers*/
main()
{
int num1,num2,sum;
clrscr();
num1=10;
num2=20;
sum=num1+num2;
printf("num1=%d\nnum2=%d\nTotal is %d",num1,num2,sum);
getch();
}

Output:-
num1=10
num2=20
Total is 30

Program 6

/*Program to print sum of two numbers*/
main()
{
int num1,num2,sum;
clrscr();
printf("Enter first no ");
scanf("%d",&num1); /* This function takes input from user */
printf("Enter second no ");
scanf("%d",&num2);

sum=num1+num2;
printf("num1=%d\nnum2=%d\nTotal is %d",num1,num2,sum);
getch();
}

Output:-
num1=_
num2=_
Total is _

QUESTION :
Write a program to input two numbers and calculate their total,multiplication,subtraction and division ?

CHAPTER 1

Fri, 20 May 2011 12:16:59 +0100

INTRODUCTION OF 'C' LANGUAGE

Program : A program is a set of instructions.A C program is required to be compiled and linked before execution

Source code (.c) -----Compilation--> Object code (.obj)

C is what is called a compiled language. This means that once you write your C program,
you must run at through a C compiler to turn your program into an executable that the computer can run (execute). The C program is the human-readable form,while the executable that comes out of the compiler is the machine-readable and executable form.
What this means is that to write and run a C program , you must have access to a C compiler.

IMPORTANT CHARACTERISTICS OF C PROGRAM

1. C is a case sensitive Programming Language.
2. Every C program must be saved in a file having extension ".c".
3. Every C program must have a main().
4. A C language statement ends with a semicolon(;).

STRUCTURE OF A C PROGRAM

Header File
macros

Global variable

main() <------Parenthesis { <----------------------------Start main function. Program statements } <----------------------------End main function

The program is compiled with ctrl+F9
For output Alt+F5