Programming Forums - Converting a word to lower case

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- - Converting a word to lower case (http://www.programmingforums.org/showthread.php?t=13296)

357mag

Jun 7th, 2007 1:03 AM

Converting a word to lower case

I've got this program that compares two words. Later on it changes the case of a word from uppercase to lowercase. I saw someplace on the web where a guy was doing this:



string lowerOrangeFruit = ConvertToLowerCase(orangeFruit)

He was including some header file called "strutils.h" and "genlib.h"

I tried it in my program but my compiler says no way.

Here is what I'm trying to do:

int main()

{

        string guitar = "guitar"; // g has an ASCII code of 103

        string piano = "Piano"; // P has an ASCII code of 80



        cout << "Does " << guitar << " come before " << piano << "?" << endl << endl;



        if (guitar < piano)

                cout << "Yes!";



        else

            cout << "No!";



        string lowerPiano = string.tolower(piano);



        return 0;

}

But I'm doing something wrong. I sense that it must be a pretty easy fix. I'll have to keep monkeying around with it.

DaWei

Jun 7th, 2007 8:28 AM

Decase your words a char at a time (loop on word length) using tolower () or toupper ().

Infinite Recursion

Jun 7th, 2007 9:31 AM

string MyToLower (string source)

{

   int i = 0;

   string temp = "";

   for (i=0;i <= source.length()-1; i++)

   {

      temp = temp + (char)(tolower(source[i]));

   }

   return temp;

}

....

string lowerPiano = MyToLower(piano);

DaWei

Jun 7th, 2007 10:35 AM

or, more efficiently (no function call in the loop): ;)

...

    int len = source.length ();

    for (i = 0; i < len; ++i)

...

Cache

Jun 7th, 2007 10:50 AM

or, using the tools already provided by the standard:

#include <cctype>

#include <string>

#include <algorithm>



// ...



std::string str = "ABCDE";

std::transform(str.begin(), str.end(), str.begin(), std::tolower);

Infinite Recursion

Jun 7th, 2007 12:13 PM

ooops, i should probably take the time to optimize the code in my lil' lib one day. :)

DaWei

Jun 7th, 2007 1:52 PM

LOL, I don't really call it optimization. When I optimize, I put an analyzer on the thang and get a good profile. It just comes from being old and having to deal with 2K-256K of memory and a 1MHz-8MHz clock. One whittled as they went, and if it still didn't woik, they got serious and whittled some more. Mailpieces and such, moving at 100-400 inches per second, wait on no man to collect the data and decide when to divert their path.

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