C++ convert word in type string variable to lowercase
c++, data-structures, string
Solution
The problem is that in the line
transform( ...., tolower() );
You are calling the function tolower rather than passing it by reference to the transform algo.. -- drop the parenthesis `()` in the tolower...
The following is the text book examples....
#include <iostream> // std::cout
#include <algorithm> // std::transform
#include <vector> // std::vector
#include <functional> // std::plus
int main () {
std::string myname("my name IS soren");
// To upper
std::transform (myname.begin(), myname.end(), myname.begin(), ::toupper);
std::cout << myname << std::endl;
// To lower
std::transform (myname.begin(), myname.end(), myname.begin(), ::tolower);
std::cout << myname << std::endl;
// Capitalize first
std::transform (myname.begin(), myname.begin()+1, myname.begin(), ::toupper);
std::transform (myname.begin()+1, myname.end(), myname.begin()+1,::tolower);
std::cout << myname << std::endl;
return 0;
}
However as other have pointed out, this does not handle multi-byte (e.g. UTF-8) characters
Problem
For sake of simplicity i chose to use a type 'string' instead of 'char'. But i am supposed to lowercase the string that i read in from the input file. I did not know at the time i would not be able to use 'tolower()'. However i did find a way using 'transform'. But i cannot get it to work and cannot find example of using it with an array of stucts. Please help. And if at all possible i also have to capitalize the first letter(s) of each state so if you could point in in the right direction would be extremely grateful. ``` #include <iostream> #include <fstream> #include <cstdlib> #include <string> #include <algorithm> struct ATdata { string state; double miles; int shelters; }; int readData( ifstream& input, struct ATdata data[] ); size_t readData( ifstream& input, struct ATdata data[], size_t MAX_ENTRIES ); int main() { ifstream input; char filename[256]; ATdata data[14]; int i; cout << "Enter input file name: "; cin >> filename; input.open( filename ); if ( input.fail() ) { cout << "Input file does not exist." << endl; exit(1); } size_t linesRead = readData( input, data, sizeof ATdata data[], size_t MAX_ENTRIES ); input.close(); return(0); } size_t readData( ifstream& input, struct ATdata data[], size_t MAX_ENTRIES ) { size_t i; int j; while ( i < MAX_ENTRIES && !input.eof() ) { ATdata entry; getline( input, entry.state ); transform( entry.state.begin(), entry.state.end(), entry.state.begin(), tolower() ); string nextLine; if ( !getline( input, nextLine ) ) { break; } istringstream iss( nextLine ); if ( !(iss >> entry.miles >> entry.shelters ) ) { continue; } data[i++] = entry; } for ( j = 0; j < 14; j++ ) { cout << data[j].state << data[j].miles << data[j].shelters << endl; } } return i; ```