How to put together a string

[Alex T]

This is a snippet of my code that does not work:

while(ascii != 32) // while character is not space
            {
                letter = (char) infile.get(); //retreive next character
                ascii = (int) letter;
                if (ascii == 32)
                    break;
                word = word + letter;
            } 

I use a text file with 3 words "this this this". The string word records the letters that are found but when it gets to the spacebar, with ascii code 32, instead prints -1 and the "y with dots over it symbol" goes into the string.

How should I fix this?

[ashitpro]

Try printing letter after line 3 and ascii after line 4
Send the results.

[donbock]

What is word? Is it a string where the plus sign is overloaded to mean concatenate or is it an integral type? If it is an integral type then computing the sum of several characters is not going to be meaningful.

What is the initial value of ascii? That is, why do you expect to be able to get into the while loop?

By the way, replace the magic number "32" with character constant ' '.

[Alex T]

Here is the complete code for your convenience:

#include <algorithm>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <map>
#include <string>
 
//NEEDS TO BE FIXED: FINDS LETTERS NOT WORDS
using namespace std;
 
typedef map <string, unsigned int> map_string_int;
typedef multimap <unsigned int, string> mmap_int_string;
 
int main() //int argc, char *argv[] insert into main for test
{
    char letter;
    int counter = 0, number, value;
    short ascii = 0;
    string word, filename;
 
    mmap_int_string::const_iterator iElementFound;
 
    map_string_int string_to_int;
    mmap_int_string int_to_string;
 
    ifstream infile;
 
    cout << "Enter name of file: ";
    getline(cin, filename);
    infile.open(filename); //argv[1] insert for test
 
    cout << endl;
 
    cout << "letter | ascii | word" << endl;
 
    while(infile.good())
    {
        while(!infile.eof())
        {
            while(ascii != -1) // while character is not space
            {
                letter = (char) infile.get();//retreive next character
                cout << letter << " | ";
                ascii = (int) letter;
                cout << ascii << " | ";
                if (ascii == -1)
                    break;
                word = word + letter;
                cout << word << endl;
            }
 
            //try to find word in index map
            map_string_int::const_iterator indexElementFound = string_to_int.find(word); 
 
            if (indexElementFound != string_to_int.end())
            {
                //if found, create another pair in multimap
                value = indexElementFound->second;
                int_to_string.insert(make_pair (value, word));
            }else{
                //if not found, create pair in both index map and multimap
                counter++;
                string_to_int.insert(make_pair (word, counter));
                int_to_string.insert(make_pair (counter, word));
            }
            word = ""; //clear word for next part of file
        }
 
        //create a list by searching multimap
        for(value = 0; value < counter; value++)
        {
            number = int_to_string.count(value);
            iElementFound = int_to_string.find(value);
            cout << iElementFound->second << " : " << number << endl;
        }
    }
 
    infile.close();
 
    char response;
    cin >> response;
 
    return 0;
}
 

My goal for this is to find the frequency of each word in the text file.

The text file has only the word "this".

For convenience, I have altered the code to make the output more meaningful: here it is.

Enter name of file: C:\\test1.txt

letter | ascii | word
t | 116 | t
h | 104 | th
i | 105 | thi
s | 115 | this
| -1 |

This is as far as it gets before the program stops functioning. Please assist.

[ashitpro]

ascii value -1 represents end of file and not space.
space has ascii value 32.

There are lots of logical problems in this code.
I have fixed the few of them. see if this code runs at your end. This is g++ compliant, you may need to make few changes.

#include <algorithm>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <map>
#include <string>
 
//NEEDS TO BE FIXED: FINDS LETTERS NOT WORDS
using namespace std;
 
typedef map <string, unsigned int> map_string_int;
typedef multimap <unsigned int, string> mmap_int_string;
 
int main() //int argc, char *argv[] insert into main for test
{
    char letter;
    int counter = 0, number, value;
    short ascii = 0;
    string word, filename;
 
    mmap_int_string::const_iterator iElementFound;
 
    map_string_int string_to_int;
    mmap_int_string int_to_string;
 
    ifstream infile;
 
    cout << "Enter name of file: ";
    getline(cin, filename);
        cout<<filename;
        //exit(0);
    infile.open(filename.c_str(),ifstream::in); //argv[1] insert for test
 
    cout << endl;
 
    cout << "letter | ascii | word" << endl;
    int out=0;
    while(infile.good() && out == 0)
    {
        while(!infile.eof() && out == 0)
        {
            while(1)
            {
                letter = (char) infile.get();//retreive next character
                cout << letter << " | ";
                ascii = (int) letter;
                cout << ascii << " | ";
                if (ascii == 32 || ascii == 10)
                {
                    break;
                }
                if (infile.eof())
                {
                    out = 1;
                    break;
                }
                word = word + letter;
                cout << word << endl;
            }
 
            //try to find word in index map
            map_string_int::const_iterator indexElementFound = string_to_int.find(word);
 
            if (indexElementFound != string_to_int.end())
            {
                //if found, create another pair in multimap
                value = indexElementFound->second;
                int_to_string.insert(make_pair (value, word));
            }else{
                //if not found, create pair in both index map and multimap
                counter++;
                string_to_int.insert(make_pair (word, counter));
                int_to_string.insert(make_pair (counter, word));
            }
            word = ""; //clear word for next part of file
        }
 
        //create a list by searching multimap
        for(value = 0; value < counter; value++)
        {
 
            number = int_to_string.count(value);
            iElementFound = int_to_string.find(value);
            if(iElementFound != int_to_string.end())
            {
              cout << endl << int_to_string.find(value)->second << " : " << number << endl;
 
            }
        }
    }
    infile.close();
 
    char response;
    cin >> response;
 
    return 0;
}
 

[donbock]

Please change line 48 from

                if (ascii == 32 || ascii == 10)

to

                if ((ascii == ' ') || (ascii == '\n'))

Even better would be

                if (isspace(ascii))

Lines 45 and 47 print the character before you check to see if it is a space. Thus, a single trailing space gets printed with each word. Is that what you wanted to do?

Don't you want to discard leading spaces too? Consider a state machine with two states: in-a-word and between-words. The initial state is between-words. Any non-whitespace character causes a transition from between-words to in-a-word. Any whitespace character causes a transition from in-a-word to between-words.

[Alex T]

Can you clarify what exactly changed in my code?

[Alex T]

Nevermind, don't. I fixed the problem. Thank you all for your help.