Question

Write a void function called FlipString. It should have 1 string parameter passed by reference. It should replace each capital letter with its lowercase letter, and each lowercase letter with its capital letter. Use the functions toUpper() and toLower() to help you.

Answer 1

#include <iostream>

using namespace std;

char toLower(char ch) {
   return ch + 32;
}

char toUpper(char ch) {
   return ch - 32;
}

void FlipString(string &s) {
   char ch;
   for(int i = 0; i < s.size(); ++i) {
      ch = s[i];
      if(ch >= 'a' && ch <= 'z') {
         s[i] = toUpper(ch);
      }
      if(ch >= 'A' && ch <= 'Z') {
         s[i] = toLower(ch);
      }
   }
}

int main() {
   string s = "Hello How are YoU?";
   FlipString(s);
   cout << "Flipped strings is: " << s << endl;
   return 0;
}