Alphabetize String

Hi,

I was just wondering if there's a function out there that will alphabetize all of the letters in a string. For example, if I typed in the string "I love New York" the function should change it to

Code:

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  eeiklnoorvwy

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Thanks, I just need it for a piece of my program.

It's a one-liner.

Code:

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std::sort(str.begin(), str.end());

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Provided the data is in a std::string, not a C-style string. It can work on C-style strings too:

Code:

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std::sort(str, str + strlen(str));

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sorry new to c++, but would i just replace 'string' with whatever the input is, and the second 'string' with the variable for the output?

Quote:

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Originally Posted by wco5002

sorry new to c++, but would i just replace 'string' with whatever the input is, and the second 'string' with the variable for the output?

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No. It actually sorts the string in place, destroying the original. To keep the original but get a sorted version, make a copy first:

Code:

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std::string sorted_string = str;
std::sort(sorted_string.begin(), sorted_string.end());

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You also need to #include <algorithm> to get the std::sort function.

str is the name of the string you want to sort. It's both the input and the output.

Code:

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

int main() {
    std::string str = "I love New York";

    std::cout << str << std::endl;
    std::sort(str.begin(), str.end());
    std::cout << str << std::endl;
}

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Something like that.

Note that that won't convert the letters to lowercase. You'll have to do that yourself if you want to -- use tolower() or toupper() from <cctype>.

does it account for uppercase and lower case letter?

Quote:

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Originally Posted by wco5002

does it account for uppercase and lower case letter?

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It treats any uppercase letter as coming "before" any lowercase letter. If you want it to disregard case, you need to write a special comparator.

Code:

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struct compare_no_case
{
    bool operator()(char a, char b)
    {
        return tolower(a) < tolower(b);
    }
};

std::sort(str.begin(), str.end(), compare_no_case());

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thanks for the pointers, got everything working good now