Write a C Program to accept a sentence and convert all lowercase characters to uppercase and vice –versa.

#include<stdio.h>
#include<conio.h>
#include<string.h>
main()
{
   char str[15];
   int i,len;
   clrscr();
   printf("\nEnter a string\n");
   gets(str);
   len=strlen(str);
   for(i=0;i<len;i++)
   {
      if(str[i]>='a' && str[i]<='z')
      str[i]=str[i]-32;
      else
      if(str[i]>='A' && str[i]<='Z')
      str[i]=str[i]+32;
   }
   printf("\nConverted string is %s",str);
   getch();
   return 0;
}