structures using c by balagurusamy

8/13/2019 Structures using C by Balagurusamy

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Structure

A Structureis a collection of different dataitems, that are stored under a common name.

Syntax:

struct structure_name{

structure element1;

structure element2;

.

};


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Example

#include

#includestruct stud

{

int regno;

char name[10];

int m1;

int m2;

int m3;

};

struct stud s;void main()

{

float tot,avg;


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printf("\nEnter the student regno,name,m1,m2,m3:");

scanf("%d%s%d%d%d",&s.regno,&s.name,&s.m1,&s.m2,

&s.m3);

tot=s.m1+s.m2+s.m3;

avg=tot/3;

printf("\nThe student Details are:");

printf("\n%d\t%s\t%f\t%f",s.regno,s.name,tot,avg);

}


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Output

Enter the student regno,name,m1,m2,m3:100

aaa

87

98

78

The student Details are:

100 aaa 263.000000 87.666664


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Structure assignment

It is possible to assign one structure

information to another structure of same type

using simple assignment statement.


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Example#include

#include

void main()

{

struct x

{int a;

}x,y;

clrscr();

x.a=10;y=x;

printf("The value of y.a is%d",y.a);

getch();

}


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Output

The value of y.a is10


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Example#include

#include

struct stud

{

int regno;

char name[10],grade;

int m1,m2,m3;float avg,tot;

} s[10];

void main()

{int i,n;

printf("\nEnter the no.of students:");

scanf("%d",&n);


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for(i=0;i


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s[i].grade='A';

else if(s[i].avg>=50)

s[i].grade='B';

else if(s[i].avg>=35)

s[i].grade='C';

}

}

printf("\nSTUDENT MARK LIST\n");

printf("\nREGNO\tNAME\tTOTAL\tAvg\tGRADE");

for(i=0;i


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Enter the no.of students:2


aaa

8998

78


bbb

5968

76

STUDENT MARK LIST

REGNO NAME TOTAL Avg GRADE

101 aaa 265.000000 88.333336 d

102 bbb 203.000000 67.666664 A


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Union

An Unionis a collection of different data items,that are stored under a common name. Heresame memory is shared by its members.

Syntax:

union union _name{

union element1;

union element2;

};


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Example:

unionresult

{

int mark;float avg;

char grade;

};

unionresult s;


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Example

#include

#includeunion stud

{

int a;

char b[2];

};

void main()

{union stud c;


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c.a=256;

printf("\nc.a value is%d",c.a);

printf("\nc.b[0] value is%d",c.b[0]);

printf("\nc.b[1] value is%d",c.b[1]);

}

Output :

c.a value is256

c.b[0] value is0

c.b[1] value is1


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256 = 00000010 00000000

Higher bit Lower bit

00000000 00000010

c.a - 2 Byte

c.b[0] 1 Byte c.b[0] 1 Byte

c.b[0] c.b[1]


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Example#include

#include

struct student{

int a;

int b;

char c;

}s;union student1

{

int a;

int b;char c;

}s1;


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void main()

{

printf("\nThe size of struct is %d",sizeof(s));

printf("\nThe size of union is %d",sizeof(s1));

getch();

}

Output :

The size of struct is 5

The size of union is 2


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Structure & Union

int int char

2 Byte 2Byte 1Byte

2 Byte

structure

int ,int, char

un ion


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Preprocessor

It is a program that processes the source

program before compilation.

It operates under the following directives

File Inclusion

Macro substitution

Conditional inclusion


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File Inclusion

It is used to include some file that contains

functions or some definitions.

Syntax:

#include (or)

#includefilename

Eg: #include#include ex.c


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Example

#include

#include

#include "addition.txt"

void main()

{int a,b;

printf("\nEnter the numbers:");

scanf("%d%d",&a,&b);

printf("The Value is %d",add(a,b));getch();

}


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addition.txt

int add(int a,int b)

{

return(a+b);

}


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Output

Enter the numbers:7

4

The Value is 11


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Example

#include

#include

#include "fact.c"

void main()

{int a;

printf("\nEnter the number:");

scanf("%d",&a);

printf("The factorial of %d! is %d",a,rec(a));

getch();

}


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fact.c

int rec(int x)

{

int f;

if(x==1)return(1);

else

f=x*rec(x-1);

return(f);

}


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Output

Enter the number:5

The factorial of 5! is 120


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Macro Substitution

It is used to define and use integer, string, or

identifier in the source program

The three forms of macros are

Simple Macro

Argumented Macro

Nested Macro


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Simp le Macro

It is used to define some constants

Syntax

# define identifier string/integer Eg:

#define pi 3.14

#define CITY chennai


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Example

#include

#include#define pi 3.14

#define CITY "chennai"

void main()

{

printf("The Value is %f",2*pi);printf("\nThe Value CITY is %s",CITY);

getch();

}

Output :

The Value is 6.280000

The Value CITY is chennai


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Argumented Macro

It is used to define some complex forms in the

source program.

Syntax:

#define identifier (v1,v2,.) string/integer

Eg:#define cube(n) (n*n*n)


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Example

#include

#include

#define cube(n) (n*n*n)

void main()

{

printf("The Value of 3 cube is %d",cube(3));

getch();

}

Output :

The Value of 3 cube is 27


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Nested Macro

Here one macro is used by another macro.

Eg:

#define a 3

#define sq a*a


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Example

#include

#include#define a 3

#define sq a*a

void main()

{printf("The Value is %d",sq);

getch();

}

Output :

The Value is 9


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Conditional Inclusion

It is used to include some conditional

statements.


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Example

#include

#include#define a 3

#ifdef a

#define c a+5

#endifvoid main()

{

printf("\nThe value C is %d",c);

getch();

}

Output :

The value C is 8


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Pointers

Pointer is a variable that contains the memory

address of another variable.


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Example:

x=5

x Variable

1002 Address

5 Value


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Example#include

#includevoid main()

{

int x=5;

printf("\n The Address of x = %u",&x);printf("\n The Value of x = %d",x);

}

OutputThe Address of x = 8714

The Value of x = 5


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Pointer Declaration

Syntax

data-type *pointer-name;

data-type - Type of the data towhich the pointer points.

pointer-name - Name of the pointer

Example: int *a;


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Accessing Variable through Pointer

If a pointer is declared and assigned to a

variable, then the variable can be accessed

through the pointer.

Example:

int *a;

x=5;

a=&x;

E l


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Example

#include

#includevoid main()

{

int x=5;

int *a;

a=&x;

printf("\n The Value of x = %d",x);

printf("\n The Address of x = %u",&x);printf("\n The Value of a = %d",a);

printf("\n The Value of x = %d",*a);

}


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Output

The Value of x = 5

The Address of x = 8758

The Value of a = 8758

The Value of x = 5


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Example:

#include

#includevoid main()

{

int y=10;

int *a;a=&y;

printf("\n The Value of y = %d",y);

printf("\n The Address of y = %u",&y);

printf("\n The Value of a = %d",a);printf("\n The Address of a = %u",&a);

}


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5001 10

8000

a y

5001

Variable

Value

Address


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Output

The Value of y = 10

The Address of y = 5001

The Value of a = 5001

The Address of a = 8000


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Null Pointer

A pointer is said to be null pointer if zero is

assigned to the pointer.

Example

int *a,*b;

a=b=0;


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Pointer to Pointer

Here one pointer stores the address of

another pointer variable.

Example:

int x=10,*a,**b;

a=&x;b=&a;


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5001 10

8000

a x

5001

Variable

Value

Address

8000

9000

b

Example


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p#include

#include

void main()

{

int a=10;

int *b,**c;

b=&a;c=&b;

printf("\n The Value of a = %d",a);

printf("\n The Address of a = %u",&a);

printf("\n The Value of b = %d",b);printf("\n The Address of b = %u",&b);

printf("\n The Value of c = %d",c);

printf("\n The Address of c = %u",&c);

}


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Output

The Value of a = 10

The Address of a = 5001

The Value of b = 5001

The Address of b = 8000

The Value of c = 8000

The Address of c = 9000


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Pointers and Functions

Call by Value

Call by Reference


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Call by value

Actual argument passed to the formal

argument.

Any changes to the formal argument does not

affect the actual argument.


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Example

#include #include

void main()

{

int x,y,swap(int,int);

printf("\nEnter value of x:");

scanf("%d",&x);

printf("\nEnter value of y:");scanf("%d",&y);


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change(x,y);

printf("\n\nValues in the Main()-->x=%d,y=%d",x,y);

}

int swap(int a,int b)

{

int c;

c=a;

a=b;

b=c;

printf("\nValues in the Function -->x=%d,y=%d",a,b);

}


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Output

Enter value of x:5

Enter value of y:6

Values in the Function -->x=6,y=5

Values in the Main()-->x=5,y=6


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Call by reference

Instead of passing value, the address of the

argument will be passed.

Any changes to the formal argument will

affect the actual argument.


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Example

#include #include

void main()

{

int x,y,change(int*,int*);

printf("\nEnter value of x:");

scanf("%d",&x);

printf("\nEnter value of y:");scanf("%d",&y);


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change(&x,&y);


}

int change(int *a,int *b)

{

int c;

c=*a;

*a=*b;

*b=c;printf("\nValues in the Function -->x=%d,y=%d",*a,*b);

}


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Output

Enter value of x:5

Enter value of y:6




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Pointer to Array

The elements of the array can also be

accessed through a pointer.

Example

int a[3]={2,3,7};

int *b;

b=a;


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Example:

#include

#includevoid main()

{

int a[3]={2,3,7};

int *b;b=a;

printf("\n The Value of a[0] = %d",a[0]);

printf("\n The Address of a[0] = %u",&a[0]);

printf("\n The Value of b = %d",b);}


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8744 2

9000

b a[0]

8744

Variable

Value

Address


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Example

#include#include

void main()

{

int a[5]={2,3,7,9,10};int i;

for(i=0;i


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2 3 7 9 10

a[0] a[1] a[2] a[3] a[4]

8724 8726 8728 8730 8732

Array

ValueAddress


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Output

The Value of a[0] = 2The Address of a[0] = 8724

The Value of a[1] = 3

The Address of a[1] = 8726




The Address of a[3] = 8730The Value of a[4] = 10


Example


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Example#include

#include

void main(){

int a[5]={1,2,3,4,5};

int i,sum=0;

int *b;

b=a;

for(i=0;i


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Output

The Sum is 15


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Pointer and Structures

Syntax:

struct structure_name

{

structure element1;

structure element2;

.

}variable,*ptr;


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Example:struct stud

{

int sno;char name[10];

int mark;

};

struct stud *s;

Example


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Example#include

#includestruct stud

{

int regno;

char name[10];int m1;

int m2;

int m3;

};struct stud s;

struct stud *t;

void main()


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void main()

{

float tot,avg;

t=&s;


scanf("%d%s%d%d%d",&s.regno,&s.name,&s.m1,&s.m2,&s.m3);

tot=s.m1+s.m2+s.m3;avg=tot/3;

printf("\nThe student Details are:");

printf("\n%d\t%s\t%f\t%f",s.regno,s.name,tot,avg);

printf("\n%d\t%s\t%f\t%f",t->regno,t->name,tot,avg);}


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Output


aaa

76

89

76

The student Details are:

1 aaa 241.000000 80.333336

1 aaa 241.000000 80.333336


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Command Line Argument

It allows the user to pass some information to

the program while running the program.

Example


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Example#include

#includevoid main(int argc,char argv[])

{

printf("\n The Argument is %s",argv[0]);

getch();

}


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Output

C:\tc>a

The Argument is C:\TC\A.EXE

l d


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String Palindrome

#include#include

#include

void main()

{char s1[15],s2[15];

printf("\nenter the string:");

scanf("%s",s1);

strcpy(s2,s1);

strrev(s1);

if(strcmp(s1 s2)==0)


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if(strcmp(s1,s2)==0)

printf("\n The string is palindrome");

elseprintf("\n The string is not a palindrome");

getch();

}

Output :

enter the string: aba

The string is palindrome

D l i C P


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Developing a C Program

The Program development life cycle is

considered as a sequence of events by the

programmer to develop the program.

The Program development life cycle containsthe following phase

Program Design

Program Coding Program Testing

P D i


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Program Design

Analysing the problem

Algorithm development

Selection of conditional and control structure

etc,.

P C di


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Program Coding

Documentation

Statement construction

Input and output format etc,.

P T ti


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Program Testing

It is the process of executing the program withsample data


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Example#include


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# c ude std o

#include

#define p 3.14

void main(){

#ifdef p

printf("\nPentium");

#else

printf("\n Celeron");

#endif

printf("\nthe value is %f",2*p);

getch();

}

Output :

Pentium

the value is 6.280000


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Example


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p#include

#include

struct stud{

int regno;

char name[10];

int m1;int m2;

int m3;

};

struct stud s;

void main()

{

float tot,avg;

int i;



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p ( g , , , , );

for(i=0;i


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aaa78

67

98

101

bbb

80

90

75

101bbb 245.000000 81.666664101bbb 245.000000 81.666664


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#include

#include

int main(void)

{

char string[15];

char *ptr, c = 'r';

strcpy(string, "This is a string");ptr = strchr(string, c);

if (ptr)

printf("The character %c is at position: %d\n", c, ptr-string);

else

printf("The character was not found\n");

return 0;

}

Example


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Example#include

#include

#include

void main()

{

char a[]="Dept";

int i=0;clrscr();

while(a[i]!='\0')

{

printf("\nThe character is %c",a[i]);i++;

}

getch();

}


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The character is D

The character is e

The character is p

The character is t


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Structure


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Structure


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Lab Exercise

C Programs

Function-with arg & return#include


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#include

void main()

{int a,b,c;

int add(int,int);

printf("\nEnter two number:");


c=add(a,b);

printf("\nSum is:%d",c);

}

int add(int x,int y)

{int z;

z=x+y;

return(z);

}

Output


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Output

Enter two number:6

7

Sum is:13

Example


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Example

#include #include

void main()

{

int x,y,change(int*,int*);printf("\nEnter value of x:");

scanf("%d",&x);

printf("\nEnter value of y:");

scanf("%d",&y);


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change(&x,&y);


}

int change(int *a,int *b)

{

int c;c=*a;

*a=*b;

*b=c;

printf("\nValues in the Function -->x=%d,y=%d",*a,*b);

}

Output


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Output

Enter value of x:5

Enter value of y:6



Factorial-Recursive Fn


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Factorial-Recursive Fn

#include#include

void main()

{

int a;int rec(int);

printf("\nEnter the number:");

scanf("%d",&a);

printf("The factorial of %d! is %d",a,rec(a));

}

int rec(int x)

{


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{

int f;

if(x==1)return(1);

else

f=x*rec(x-1);

return(f);

}

Output:

Enter the number:5

The factorial of 5! is 120

Example: Working of 3!


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Example: Working of 3!

Matrix Multiplication


109/128

#include

#include

void main(){

int i,j,k,r1,r2,c1,c2;

int a[5][5],b[5][5],c[5][5];

clrscr();step1:

printf("\n Enter the size of matrix A \n");

scanf("%d%d",&r1,&c1);

printf("\n Enter the size of matrix B \n");

scanf("%d%d",&r2,&c2);if(c1==r2)

goto step2;

else

goto step1;

step2:

printf("\n Enter the elements of matrix A \n");


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for(i=0;i


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{

for(j=0;j


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2

Enter the size of matrix B:2

2Enter the elements of matrix A

4

4

4

4Enter the elements of matrix B

4

4

44

The resultant matrix is

32 32

32 32


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Lab Ex:9,Finding area, circumference


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of circle

#include#include

void main ( )

{

int r;

float area,c;

clrscr( );

printf(" \nEnter the value of r:");scanf("%d",&r);

area=3.14*r*r;


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;

c=2*3.14*r;

printf(" \nThe area is :%f",area);printf(" \nThe circumference is :%f",c);

getch( );

}

Output :

Enter the value of r:7

The area is :153.860001

The circumference is :43.959999

Lab Ex:9,Conversion of Celsius to

h h


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Fahrenheit

#include#include

void main ( )

{

float c,f;clrscr( );

printf(" \nEnter the value of c:");

scanf("%f",&c);

f=(c*1.8)+32;

printf(" \nThe Fahrenheit is :%f",f);

getch( );

}


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Enter the value of c:35

The fahrenheit is :95.000000

Lab Ex:11,Arithmetic operations


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#include

#include

void main()

{

int a,b,c,d,e,f;clrscr();

printf("\nEnter the values of A and B:");


c=a+b;d=a-b;

e=a*b;

f=a/b;


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printf("\nThe values of A + B:%d",c);printf("\nThe values of A - B:%d",d);

printf("\nThe values of A * B:%d",e);

printf("\nThe values of A / B:%d",f);getch();

}

Output


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Output

Enter the values of A and B:6

3

The values of A + B:9

The values of A - B:3

The values of A * B:18

The values of A / B:2

Lab.Ex13,Largest among 3 nos#incl de


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#include

#include

void main ( ){

int a,b,c;

clrscr( );

printf(" \nEnter the value of a:");

scanf("%d",&a);

printf(" \nEnter the value of b:");

scanf("%d",&b);


scanf("%d",&c);


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if((a>b)&&(a>c)){

printf(" \nA is Big");

}

else

{

if(b>c)

printf(" \nB is Big");

else

printf(" \nC is Big");}

getch( );

}

Output


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p

Enter the value of a:5

Enter the value of b:7


B is Big

String Palindrome


124/128

g

#include#include

#include

void main()

{

int len,i,j;

char str[15];

clrscr();

printf("\n Enter the string:");

scanf("%s",str);len=strlen(str);

for(i=0,j=len-1;i


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{

if(str[i]!=str[j])

{

printf("\nThe String is not a palindrome");

getch();

exit(0);

}

}printf("\nThe String is a palindrome");

getch();

}

Output :

Enter the string:abcba

The String is a palindrome

Lab.Ex:14,Quadratic Equation#i l d di h


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#include

#include

#includevoid main ( )

{

int a,b,c,d,r1,r2;

clrscr( );printf(" \nEnter the value of a:");

scanf("%d",&a);

printf(" \nEnter the value of b:");

scanf("%d",&b);


scanf("%d",&c);

d=b*b-4*a*c;

if(d 0)


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if(d>=0)

{

r1=(-b+sqrt(d))/(2*a);r2=(-b-sqrt(d))/(2*a);

printf(" \nThe roots are %d,%d",r1,r2);

}else

{

printf(" \nThe roots are imaginary");

}

getch( );

}

Output


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p

Enter the value of a:1

Enter the value of b:4


The roots are -2,-2

structures using c by balagurusamy

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