Write a C program to Swap two numbers using pointers

What are Pointers?

A pointer is a variable whose value is the address of another variable, i.e., direct address of the memory location. Like any variable or constant, you must declare a pointer before using it to store any variable address.

The general form of a pointer variable declaration is −

• type *var-name;

Here, type is the pointer’s base type; it must be a valid C data type and var-name is the name of the pointer variable.

The asterisk * used to declare a pointer is the same asterisk used for multiplication. However, in this statement the asterisk is being used to designate a variable as a pointer.

The unary or monadic operator & gives the “address of a variable’”.

The indirection or dereference operator * gives the “contents of an object pointed to by a pointer”.

Below is the source code for C program to Swap two numbers using pointers which is successfully compiled and run on Windows System to produce desired output as shown below :

SOURCE CODE : :

/*  C program to Swap two numbers using pointers  */

#include<stdio.h>
#include<conio.h>

int main()
{
    int num1,num2;
    int *a,*b,*temp;

    printf("Enter 1st number :: ");
    scanf("%d",&num1);
    printf("\nEnter 2nd number :: ");
    scanf("%d",&num2);

    a=&num1;
    b=&num2;

    printf("\nBefore Swapping ::\n\n\ta = %d\tb = %d\n",*a,*b);

    temp=a;
    a=b;
    b=temp;

    printf("\nAfter Swapping ::\n\n\ta = %d\tb = %d\n",*a,*b);

    return 0;
}

Output  : :

/*  C program to Swap two numbers using pointers  */

Enter 1st number :: 5

Enter 2nd number :: 9

Before Swapping ::

        a = 5   b = 9

After Swapping ::

        a = 9   b = 5

Process returned 0

Above is the source code for C program to Swap two numbers using pointers which is successfully compiled and run on Windows System.The Output of the program is shown above .