converting input into lowercase?

[swiftys]

Hey, first of all I'd just like to say sorry, sorry if this is brought up, some newb comes in asking questions that are just... stupid >.<
I'm actually pretty **** new to C++, but I'm getting there :)

I'm wondering if there is anyway I can convert someone's input in lowercase, whether it be from a variable or from when the user enters in the input.

Thanks ;)

[humptydumpty]

did u checked out MSDN have a look for the function isUpper() toLower() .


Example from MSDN


char msg[] = "Some of THESE letters are Capitals\r\n";
char *p;

void main( void )
{
_cputs( msg );

/* Reverse case of message. */
for( p = msg; p < msg + strlen( msg ); p++ )
{
if( islower( *p ) )
_putch( _toupper( *p ) );
else if( isupper( *p ) )
_putch( _tolower( *p ) );
else
_putch( *p );
}
}




Alternative is Simply read the string make a loop read each character from the string and check it's ascii value if it is between 65 to 90 simply add 32 to the original value .and store the character back to some array.
Thanx

[SuperKoko]

Use std::tolower

[Paul McKenzie]

Hey, first of all I'd just like to say sorry, sorry if this is brought up, some newb comes in asking questions that are just... stupid >.<
I'm actually pretty **** new to C++, but I'm getting there :)

I'm wondering if there is anyway I can convert someone's input in lowercase, whether it be from a variable or from when the user enters in the input.

Thanks ;)

#include <algorithm>
#include <string>
#include <cctype>
#include <iostream>

using namespace std;

int main()
{
string input;
getline(cin, input);

// convert input to lower case
transform(input.begin(), input.end(), input.begin(), std::tolower);
cout << input;
}

Regards,

Paul McKenzie

[swiftys]

thank you very much for your help guys.

cheers!

;)

[alnikolov]

#include <algorithm>
#include <string>
#include <cctype>
#include <iostream>

using namespace std;

int main()
{
string input;
getline(cin, input);

// convert input to lower case
transform(input.begin(), input.end(), input.begin(), std::tolower);
cout << input;
}

Regards,

Paul McKenzie

std::tolower requires 2 parameters and cannot be used like this.

You can use C-library tolower instead or you can do this:


char makelower( char ch)
{
return std::tolower(ch, locale());
}

int main()
{
string input;
getline(cin, input);

// convert input to lower case
transform(input.begin(), input.end(), input.begin(), makelower);
cout << input;
}


Aleksandar Nikolov

[Philip Nicoletti]

std::tolower requires 2 parameters and cannot be used like this.

You can use C-library tolower instead or you can do this:


Your method is the safest way (it will compile on all compilers). But
whether Paul's code is incorrect is unclear (at least to me).

1) see Josuttis' comments near the very top at:

http://www.josuttis.com/libbook/new.html

2) All compilers that I know of accept this (including comeau):


#include <string>
#include <cctype>
#include <algorithm>

int main()
{
std::string s = "Hello World";
std::transform(s.begin(),s.end(),s.begin(),std::toupper);
}


3) However, if you include <iostream> (among a few others headers),
g++ will give a compiler error.