Q33 Write a program in C to read a sentence and replace lowercase characters by uppercase and vice-versa .

Write a program in C to read a sentence and replace lowercase characters by uppercase and vice-versa .

#include <stdio.h>
#include <string.h>
#include <ctype.h>
void main()
{
  char str[100];
  int ctr, ch, i;
     printf("Input the string : ");
       fgets(str, sizeof str, stdin);  
  i=strlen(str);
  ctr = i;
  printf("\nThe given sentence is   : %s",str);
  printf("After Case changed the string  is: ");
  for(i=0; i < ctr; i++)
  {
    ch = islower(str[i]) ? toupper(str[i]) : tolower(str[i]);
    putchar(ch);
   }
   printf("\n\n");
}  

Output

Input the string : Hello

The given sentence is   : Hello
After Case changed the string  is: hELLO