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JackDurden

Dec 2nd, 2008 3:29 pm

Using string as char array

How would I delete one char from a string?

string aWord = "question?";



while(aWord[i])

        {

        if(isalpha(aWord[i]))printf ("character %c is alphabetic\n",aWord[i]);

        else

                delete[i]aWord;

    i++;

  }

VernonDozier

Dec 2nd, 2008 3:37 pm

Re: Using string as char array

Quote:

Originally Posted by JackDurden (Post 748953)

How would I delete one char from a string?

string aWord = "question?";



while(aWord[i])

        {

        if(isalpha(aWord[i]))printf ("character %c is alphabetic\n",aWord[i]);

        else

                delete[i]aWord;

    i++;

  }

Use the replace function from string:

http://www.cplusplus.com/reference/s...g/replace.html

string aWord = "abcdef";

aWord.replace (3, 1, "");

aWord

now contains "abcef";

Edit: Or just use erase:

aWord.erase (3, 1);

Has the same effect.

Freaky_Chris

Dec 2nd, 2008 3:45 pm

Re: Using string as char array

Note you can use find() or find_first_of() etc to get the index of the character youare after.

Chris

JackDurden

Dec 2nd, 2008 3:55 pm

Re: Using string as char array

Well that sort of works but if the char I want to delete/erase is at the end of the string my compiler crashes. I dont understand how to delete/erase a char that is not an alphanumeric type.

  int i=0;

 string aWord = "abcdf!";



while(aWord[i])

        {

        if(isalpha(aWord[i]))printf ("character %c is alphabetic\n",aWord[i]);

        else

                aWord.erase (i, 1);

    i++;

  }

  cout<<aWord;

Laiq Ahmed

Dec 2nd, 2008 4:02 pm

Re: Using string as char array

Quote:

Originally Posted by JackDurden (Post 748953)

How would I delete one char from a string?

string aWord = "question?";



while(aWord[i])

        {

        if(isalpha(aWord[i]))printf ("character %c is alphabetic\n",aWord[i]);

        else

                delete[i]aWord;

    i++;

  }

I can give you two ways. one through STL & other through using the strings only

       string strWord = "Hello, World!";

        string strResult = "";



        for(size_t idx = 0; idx < strWord.size(); ++idx) {

                if (isalpha(strWord[idx])) {

                        strResult += strWord[idx];

                }

        }

        cout<< strResult<<endl;

Another Way

  string strWord = "Hello, World! Laiq?";

        size_t pos = 0;



        for(size_t idx = 0; idx < strWord.size(); ++idx) {

                if (isalpha(strWord[idx])) {

                        strWord[pos] = strWord[idx];

                        ++pos;

                }

        }

        strWord.resize(pos);



        cout<< strWord <<endl;

Little more tricky.

   Check the remove_if (...)

Hope the above techniques might help you in understanding ?

VernonDozier

Dec 2nd, 2008 4:42 pm

Re: Using string as char array

Quote:

Originally Posted by JackDurden (Post 748969)

Well that sort of works but if the char I want to delete/erase is at the end of the string my compiler crashes. I dont understand how to delete/erase a char that is not an alphanumeric type.

  int i=0;

 string aWord = "abcdf!";



while(aWord[i])

        {

        if(isalpha(aWord[i]))printf ("character %c is alphabetic\n",aWord[i]);

        else

                aWord.erase (i, 1);

    i++;

  }

  cout<<aWord;

Your program ran for me. I don't know what error you got, but if it is an index-out-of-range/segmentation fault error, you may want to change this:

while (aWord[i])

while (i < aWord.length ())

That might make a difference, might not. As to your other problem, only increment i if aWord[i] is a letter. erase and replace will cause the indexes to change, so some characters will be skipped if you use erase/replace AND increment i.

cikara21

Dec 2nd, 2008 5:22 pm

Re: Using string as char array

Check the size..

  

int i=0;

string aWord = "abcdf!";



while(aWord[i])

{

   if(isalpha(aWord[i]))

      printf ("character %c is alphabetic\n",aWord[i]);

   else

   {

        aWord.erase (i, 1);

      //..Is idx > length

       if(i>aWord.size())

          break;

       i--;

   }

   i++;

}

cout<<aWord;

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