convert uppercase to lowercase
// C++ program to convert whole string to
// uppercase or lowercase using STL.
#include<bits/stdc++.h>
using namespace std;
int main()
{
// su is the string which is converted to uppercase
string su = "Jatin Goyal";
// using transform() function and ::toupper in STL
transform(su.begin(), su.end(), su.begin(), ::toupper);
cout << su << endl;
// sl is the string which is converted to lowercase
string sl = "Jatin Goyal";
// using transform() function and ::tolower in STL
transform(sl.begin(), sl.end(), sl.begin(), ::tolower);
cout << sl << endl;
return 0;
}