Menu Driven C program to calculate Area of Square, Rectangle

This program demonstrates the use of switch() case :

 #include<stdio.h>  
 #include<conio.h>  
 #include<stdlib.h>  
 main()  
 {  
  int ch;  
  float s,l,b;  
  float arect,asquare;  
  clrscr();  
  do  
  {  
  printf("\t Main Menu\n");  
  printf("\t 1. Area of Rectangle.\n");  
  printf("\t 2. Area of Square.\n");  
  printf("\t 3. Exit\n");  
  printf("\n\tEnter your choice:\n");  
  scanf("%d",&ch);  
  switch(ch)  
  {  
   case 1 : printf("\n\tEnter length and bredth:\n");  
         scanf("%f%f",&l,&b);  
         arect=l*b;  
         printf("\n\tArea of rectangle is : %f\n\n",arect);  
         break;  
   case 2 : printf("\n\tEnter side of the Square:\n");  
         scanf("%f",&s);  
         asquare=s*s;  
         printf("\n\tArea of Square is : %f\n\n",asquare);  
         break;  
   case 3 : exit(0);  
  }  
  }  
  while(ch>=1 && ch<=4);  
 }  

OUTPUT :

Main Menu
1. Area of Rectangle.
2. Area of Square.
3. Exit

Enter your choice:
1
Enter length and bredth:
2
4

Area of rectangle is : 8.000000

Main Menu
1. Area of Rectangle.
2. Area of Square.
3. Exit

Enter your choice:
3