C++ towlower comparison with original character fails?

Question

I have the following code in C++:

string StringTest = "Test";
bool OriginalWord = true;
for (unsigned int i = 0; i < StringTest(); i++) {
    string Character = towlower(StringTest[i]);
    string CharacterOriginal = StringTest[i];
    if (Character != CharacterOriginal) {
        //t vs. T should trigger false, but never happens?
        //e vs. e should trigger true
        //s vs. s should trigger true 
        //t vs. t should trigger true
        OriginalWord = false;
        }
    }

Note that I use towlower instead of tolower.

This always results in a OriginalWord=true situation. However, e.g. Test should give me back OriginalWord=false. Because towlower(T) will result in t and the CharacterOriginal = T, which means they are not the same and thus OriginalWord=false?

What am I doing wrong? I guess it has to do something with the towlower function

That code should not even compile, because you try to initialize a `std::string` from a single character (technically a `std::wint_t`) (and other problems). — Some programmer dude, Apr 21 '17 at 11:35
You are mixing up methods for wstring (towlower) with string methods (tolower) — Martze, Apr 21 '17 at 11:36
@Martze, this sounds like where my thoughts where going, but I have no idea how to fix this issue. I am quite new to C++ — TVA van Hesteren, Apr 21 '17 at 11:37

score 0 · Answer 1 · answered Apr 21 '17 at 12:09

You have some trouble with type conversions, which wouldn't fly with stricter compiler flags. Please see the comments in the code fragment below:

string StringTest = "Test";
bool OriginalWord = true;
for (unsigned int i = 0; i < StringTest.size(); i++) 
// do you mean StringTest.size() instead of StringTest()?
{
    wint_t Character = towlower(StringTest[i]);
    wint_t CharacterOriginal = StringTest[i];
// can't convert a char to a string (or const char *)
// did you meant to use wint_t instead of string?
    if (Character != CharacterOriginal) 
    {
        //t vs. T should trigger false, but never happens?
        //e vs. e should trigger true
        //s vs. s should trigger true 
        //t vs. t should trigger true
        OriginalWord = false;
    }
}

score 0 · Answer 2 · answered Apr 21 '17 at 12:53

Okay, there some troubles in your code, first:

string StringTest = "Test"; // you created StringTest as a single variable
 //in the next steps you use it all the time as a array, lets change that.

int count = 10;
string StringTest[count] = { "Test", "test","Test", "test","Test", "test","Test", "test","Test", "test" };

for (unsigned int i = 0; i < StringTest(); i++) // you must use the size of string so:
for (unsigned int i = 0; i < count; i++)

Ibrahim · Answer 3 · 2017-04-21T11:37:55.953

-1

string Character false usage, it must be a char Because tolower returns int(char) not a string. Also to get length of string -> StringTest.size();

The edited code is here!

string StringTest = "Test";
bool OriginalWord = true;
for (unsigned int i = 0; i < StringTest.size(); i++) {
    char Character = tolower(StringTest[i]);
    char CharacterOriginal = StringTest[i];
    if (Character != CharacterOriginal) {
        OriginalWord = false;
    }
}

edited Apr 21 '17 at 11:37

answered Apr 21 '17 at 11:35

Ibrahim

320
2
7

This is not using towlower but tolower and is not an option. – TVA van Hesteren Apr 21 '17 at 11:36
2

then use wstring instead of string – Martze Apr 21 '17 at 11:37

C++ towlower comparison with original character fails?

3 Answers3