In this tutorial, we will be discussing a program to understand conversion of whole string to uppercase or lowercase using STL in C++.
To perform this transformation, C++ STL provides toupper() and tolower() functions to convert to uppercase and lowercase respectively.
Example
#include<bits/stdc++.h>
using namespace std;
int main(){
string su = "Tutorials point";
transform(su.begin(), su.end(), su.begin(), ::toupper);
cout << su << endl;
string sl = "Tutorials Point";
transform(sl.begin(), sl.end(), sl.begin(), ::tolower);
cout << sl << endl;
return 0;
}Output
TUTORIALS POINT tutorials point