to upper string c++ code example

Example 1: convert all characters in string to uppercase c++

transform(str.begin(), str.end(), str.begin(), ::toupper);

Example 2: uppercase capitalise character in string c++

str[i] = toupper(str[i]);

Example 3: convert from uppercase to lowercase c++

int i = 0;
    while(str[i])
    {
        if(str[i] == std::toupper(str[i]) && std::isalpha(str[i]) == 1024)
        str[i]+= 32;
        ++i;
    }