Program to show nesting of macros

#include<stdio.h>

#define SQU(x)((x)*x)

#define CUBE(x)(SQU(x)*x)

int main()

{         

          int x,y;

          clrscr();

          x=SQU(3);

          y=CUBE(3);

          printf("\nSquare of 3 : %d",x);

          printf("\nCube of 3 : %d",y);

          return(0);

}

Program to demonstrate pointer to function

#include<stdio.h>

main()

{

          void mess();

          void (*ptr)();

          ptr=mess;

          clrscr();

          printf("Address of the function is %d\n",ptr);

          (*ptr)();

}             

      void mess()

      {

          printf("I am in the subprogram\n");

      }

Program to demonstrate enumerated data types.

#include<stdio.h>

enum month {Jan,Feb,Mar,Apr,May,June,July,Aug,Sep,Oct,Nov,Dec,Next};

main()

{

          int m;

          float pay,sum=0;

          printf("\n");

          for(m=Jan;m<=Dec;m++)

          {

                   printf("Enter the pay of month %d :",m+1);

                   scanf("%f",&pay);

                   sum+=pay;

          }

          printf("Total Salary =%f",sum);

}

Program to demonstrate dynamic memory allocation

#include<stdio.h>

#include<string.h>

#include<stdlib.h>

main()

{

          char *mem_allocation;

          clrscr();

          mem_allocation= malloc( 20* sizeof(char));

          if(mem_allocation==NULL)

          {

           printf("couldn't able to allocate requested memory\n");

          }

          else

          {

                   strcpy(mem_allocation,"Besties");

      }

      printf("Dynamically allocated memory                                  content:""%s",mem_allocation);

           free(mem_allocation);

}

Program to demonstrate use of #define

 #include<stdio.h>

#define NAME "vokytoky"

#define AGE 15

int main()

{       clrscr();

          printf("%s is over %d years old.\n",NAME,AGE);

          return 0;

}

Program to demonstrate conditional compilation.

#include<stdio.h>

int main()

{              

          int i=2;

          clrscr();

          #ifdef DEF

          {

                   i*=i;

          }

          #else

          {

                   printf("The answer is %d\n",i);

          }

          #endif

          return 0;

}

Program to demonstrate array of strings

#include<stdio.h>

#include<string.h>

void main()

{                  

          char name[35][21];

          int n,i;

          clrscr();

          printf("Enter numbers of students");

          scanf("%d",&n);

          printf("Enter the %d students name\n",n);

          for(i=0;i<=n;++i)

          {

                   gets(name[i]);

          }

     printf("\n List of students is");

          for(i=0;i<=n;++i)

          puts(name[i]);

}