c++ lowercase string code example

Example 1: check if character in string is uppercase c++

if (isupper(str[i])) {
	// str[i] is uppercase
}

Example 2: tolower funciton in cpp

transform(s.begin(), s.end(), s.begin(), ::tolower);

Example 3: tolower in c++

#include <cctype>
#include <iostream>
#include <cstring>
#include <cstdio>

using namespace std;

int main()
{
    char str[] = "John is from USA.";

    cout << "The lowercase version of \"" << str << "\" is " << endl;

    for (int i=0; i<strlen(str); i++)
        putchar(tolower(str[i]));
    
    return 0;
}

Example 4: c++ string functions lowercase

transform(su.begin(), su.end(), su.begin(), ::toupper);
transform(sl.begin(), sl.end(), sl.begin(), ::tolower);