C PROGRAMMING BASICS- COMPUTER PROGRAMMING UNIT II

PREPARED BY K,NITHIYA
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CHARACTER SET
C CHARACTER SET
Execution Character
Set
Source Character Set
DigitsAlphabets Special Character
White
Space
Character
Space
Escape
Sequence
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A Character denotes an alphabet, digit or a
special character.
Lowercase Letters – A,B,C….. Z
Uppercase Letters - a,b,c…… z
Digits – 0,1,2,3,…7,8,9
+ Plus Sign - Minus Sign , Comma
* Asterisk / Slash = Equal to
@ At Symbol < Less Than : Colon
; Semicolon
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It will work at the execution time only and it cannot be printed.
It always represented by a backslash() followed by a character.
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 The smallest individual units of a c program are
known as tokens
 It can be categorized into following ways
C tokens
operators
Special
symbolstringconstantsIdentifiersKeywords
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 Keyword is a reserved keyword that has a particular meaning
 It should be in lower case
 There are 32 keywords in c language
S.
NO
keyword S.
NO
keyword S.NO keyword S.
NO
keyword keyword
1 auto 8 do 15 goto 22 signed 29.unsigned
2 break 9 double 16 if 23 sizeof 30.void
3 case 10 else 17 int 24 static 31.volatile
4 char 11 enum 18 long 25 struct 32.while
5 const 12 extern 19 register 26 switch
6 continue 13 float 20 return 27 typedef
7 default 14 for 21 short 28 union
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 It can be a variable name and function name etc.
 Maximum length of an identifier is 31
 Special character are not allowed except(_).
Valid invalid
nithiya Nithya#
NITHIYA Nith ya ->blank space
Nithya3 Auto
Nithya 3nithya
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10
-356
4600.5
-0.963
‘A’
‘*’
“A”
“CSC”
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Variables are named locations in memory that are used to
hold a value that may be modified by the program.
K5.ico ANIMATAY006.ICO
The syntax for declaring a variable is
Data type Variablename;
Valid Examples :
CSC avg_val
m1 Chennai Anu
mark_1
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RULES for framing a variable :
The first character in the Variable name must be an alphabet
Alphabets can be followed by a number of digits or
underscores
No commas or Blank spaces are allowed within a variable
name
No Special character other than Underscore(_) can be used in
a variable name.
The variable name should not be a keyword
Variable names are case sensitive
It should not be of length more than 31 characters
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INTIALIZING VARIABLE
Assigning some value to the variable is known as intialization
SYNTAX:
Data type variable name=value;
Example
Int a=10;
SCOPE OF VARIABLE
1.Local variable
2.Global variable
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Scope of
variable
definition example
Local
variable
Declared
inside the
block
main()
{
Int a=8; // local
variable
}
Global
variable
Declared
before the
main function
Int a=8;
Main()
{
//no of statement
}
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C data types
Empty data
type
User defined
data type
Derived or
secondary data
type
Primary data
type
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PRIMARY DATA TYPES
int float chardouble
1.PRIMARY DATA TYPES

S.N
O
Data
Type
Explanation Size(bytes) CONTRO
L
STRING
RANGE SYNTAX EXAMPLE
1 int It store numeric values
without decimal point
Example:9,10,23
2 bytes %d or %i -32,768 to
+32,767
int
Variable_na
me;
int roll_no;
2 float It store the numeric
values with decimal
point
Example:3.12,47.098
4 bytes %f or %g 3.4E-38 to
3.4E+38
Float
Variable_na
me;
float a;
3 double It store the big number
of decimal point
Example:2.13455
8 bytes %if 1.7E-308 to
1.7E+308
Double
Variable
name;
double b;
4 char It store the single
character
Example:’a’,’9’
1 bytes %c -128 to +127 Char
Variable
name;
char
a=“nithiya”;
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1.Array
An array is a collection of variable of same data type
SYNTAX: Datatype array_name[array size];
Example: int a[10];
2.Structures
it stores the multiple values of same or different data type
under a single name
Syntax:
Struct <struct name>
{
Member 1;member 2;};
DERIVED DATA
TYPE
array pointersunionsstructures

EXAMPLE:
Struct Student
{
Char name[10];
Int roll_no;
};
3.UNION
A union is store the multiple values of same or different data type
SYNTAX:
union <union name>
{
Member 1; member 2;
}
EXAMPLE:
Union student
{
Char name[25];
};
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4.POINTERS
A pointer is holds the memory address of another variable
SYNTAX:
Data type *variable name
EXAMPLE : int *a
EMPTY DATA TYPE
i)Void
its represents an empty value
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1.Type Definition
Example: Typedef int age;
age male,female
2.Enumerated Datatype
Example :
enum mon{jan,feb,mar,apr,may,jun,jul,aug,sep,oct,nov,dec };
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USER DEFINED DATA TYPE

Control
statement
conditional unconditional
selective looping
Nested if else
Simple if
If else
If-else if
ladder
Switch case
while
do while
for
goto
break
continue
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 A program is a sequence of one or more instructions
 The condition will check whether the particular
condition are true (or) not.
 1.SIMPLE IF STATEMENT
 If the condition is true the set of statements are
executed
 SYNTAX

if(condition)
{
Statement 1;
}
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To find the given no is even or odd
#include<stdio.h>
#include<conio.h>
main()
{
int no;
clrscr();
printf(“n Enter the number”);
scanf(“%d”,&no);
if(no%2==0)
{
printf(The given no is even”);
}}
Output
Enter the number
24
The given no is even
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2.if else statement
It is a two way decision making statement
SYNTAX:
if(condition)
{
Statement 1;
}
else
{ false statement;
}
#include<stdio.h>
#include<conio.h>
main()
{
int no;
clrscr();
if(no%2==0)
{
}
else
{
Printf(“The given no is odd”);
}
#include<stdio.h>
#include<conio.h>
main()
{
int no;
clrscr();
if(no%2==0)
{
}
else
{
Printf(“The given no is odd”);
}
Output
Enter the number
25
The given no is odd
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 The number of logical conditions is checked for executing various
statements
 SYNTAX
 if(condition 1)
 {
 True statement 1;
 }
 else
 {
 if(condition 2)
 {
 True statement 2;
 }
 else
 {
 False statement
}}
#include<stdio.h>
#include<conio.h>
Main()
{
int a,b,c;
clrscr();
printf(“Enter a,b,c”);
scanf(“%d%d%d”,&a,&b,&c);
if((a>b)&&(a>c))
{
printf(“A is greater”);
}
else
{
If(b>c)
{
printf(“B is greater”);
}
else
{
printf(“C is greater”);
}}}
Output
Enter the values of a,b,c
4
2
3
A is greater

Nested if-else can be chained with one another
Syntax:
if(condition 1)
{
Statement 1;
}
else if(condition 2);
{
Statement 2;
}
else if(condition 3)
{
statement;
}
else
{
Final statement
}
#include<stdio.h>
#include<conio.h>
Main()
{
int a,b,c;
clrscr();
printf(“Enter a,b,c”);
scanf(“%d%d%d”,&a,&b,&c);
if(a>b)
{
If(a>c)
{
printf(“A is greater”);
}
else
{
} }
else if(b>c)
{
printf(“B is greater”);
}
else
{
}}
Output
Enter the values of a,b,c
4
2
3
A is greater
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 If the value matches with case constant, this particular case statement is executed.
if not default is executed.
 SYNTAX:
 Switch (variable)
 {
 Case constant 1:
 statement 1;
 Break;
 Case constant 2:
 Statement 2;
 Break;
 ..
 ..
 default:
 Default statement;
 }
#include<stdio.h>
#include<conio.h>
Main()
{
int a=10,b=5;
char symbol;
clrscr();
printf(“Enter the symbol”);
scanf(“%c”,&symbol);
switch(symbol)
{
case’+’:
result=a+b;
break;
case’-’:
result=a-b;
break;
case’*’:
Result=a*b;
Break;
Case’/’:
Result=a/b;
break;
case’%’:
Result=a%b;
break;
}
Default:
Printf(“invalid symbol”);
}
Printf(“the result is %d”,result);
}
Output
Enter the symbol:+
The result is 15
Enter the symbol:%
The result is 0
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C PROGRAMMING BASICS- COMPUTER PROGRAMMING UNIT II

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C PROGRAMMING BASICS- COMPUTER PROGRAMMING UNIT II