Pointers in C

What is pointer?

Pointer is a variable which holds the address of another variable.  By using this pointer variable we may call that particular memory location.

Malloc()

Realloc()

Freealloc()

Calloc()

#include<stdio.h>

#include<conio.h>

void main()

{

int x,*ptr;

ptr=&x;

clrscr();

printf(“Enter an integer:”);

scanf(“%d”,ptr);

printf(“The value of %d\n”,x);

getch();

}

%u to find out the address of the pointer

#include<stdio.h>

#include<conio.h>

void main()

{

int x,*ptr;

ptr=&x;

clrscr();

printf(“Enter a number:”);

scanf(“%d”,&x);

printf(“Value of the number=%d\n”,x);

printf(“Address of the pointer ptr=%u\n”,ptr);

getch();

}

#include<stdio.h>

#include<conio.h>

void main()

{

int x,y,big;

int *ptr,*ptr1;

ptr=&x;

ptr1=&y;

clrscr();

printf(“Enter two numbers:\n”);

scanf(“%d%d”,&x,&y);

if(*ptr>*ptr1)

big=*ptr;

else

big=*ptr1;

printf(“Biggest number is:%d\n”,big);

getch();

}

#include<stdio.h>

#include<conio.h>

void main()

{

char *name;

char name1[15];

clrscr();

printf(“Enter a string:”);

scanf(“%s”,name1);

*name=name1;

printf(“%s”,*name);

getch();

}

#include<stdio.h>

#include<conio.h>

void main()

{

int *c,*d;

clrscr();

printf(“Enter two numbers:”);

scanf(“%d%d”,c,d);

printf(“\n The sum of two number=%d”,*c+*d);

getch();

}

#include<stdio.h>

#include<conio.h>

void main()

{

int *x,*y,p1,p2;

x=&p1;

y=&p2;

clrscr();

printf(“Enter two numbers:”);

scanf(“%d%d”,&p1,&p2);

printf(“Address=\n”);

printf(“%d\n”,*x);

printf(“%d\n”,*y);

printf(“%d\n”,p1);

printf(“%d\n”,p2);

getch();

}

#include<stdio.h>

#include<conio.h>

void main()

{

int a,b;

clrscr();

printf(“Enter two numbers:”);

scanf(“%d%d”,&a,&b);

exchange(&a,&b);

getch();

}

exchange(int *aa,int *bb)

{

int *t;

*t=*aa;

*aa=*bb;

*bb=*t;

printf(“A value:%d\n”,*aa);

printf(“B value:%d\n”,*bb);

}

#include<stdio.h>

#include<conio.h>

void main()

{

int sum(int *,int *)

int a,b,s;

clrscr();

printf(“\n Enter A:”);

scanf(“%d”,&a);

printf(“Enter B:”);

scanf(“%d”,&b);

s=sum(&a,&b);

printf(“The sum:%d”,s);

getch();

return;

}

int sum(int *x,int *y)

{

return(*x+*y);

}

#include<stdio.h>

#include<conio.h>

void main()

{

int a[100],temp,*pa,*pb;

pa=&a[0];

pb=&a[1];

clrscr();

printf(“Enter the values:”);

for(pa=a;pa<a+10;pa++)

{

scanf(”%d”,&pa);

}

for(pa=a;pa<a+10;pa++)

{

for(pb=a;pb<a+10;pb++)

{

if(*pa>*pb)

{

temp=*pa;

*pa=*pb;

*pb=temp;

}

}

}

printf(“The sorted list\n”);

for(pa=a;pa<a+10;pa++)

printf(“\n %d\n”,*pa);

getch();

}