void main()
           {
              int day;
              clrscr();
              printf("enter any number from 1-7=");
               scanf("%d",&day);

                   switch(day)
                     {
                       case 1 :
                               printf("\n monday");
                                break;
 
                       case 2 :
                               printf("\n tuesday");
                                break;
      
                       case 3 :
                                printf("\n wednesday");
                                break;
            
                       case 4 :
                                printf("\n thursday");
                                break;

                       case 5 :
                               printf("\n friday");
                                break;
 
                       case 6 :
                                printf("\n saturday");
                                 break;

                       case 7 :
                                printf("\n sunday");
                                break;

                       default :
                                 printf("invalid number");
                                  break;
                    }
    
             getch();

           }


        output :
                 enter any number from 1-7=2
                  tuesday                 

                    or
 
                   enter any number from 1-7=8
                    invalid number