using namespace std

couple questions......

1. what does using namespace std exactly do?

2. does it do something to the way eof works?
i had a program that worked when i didnt have using namespace std but i needed to add it for other reasons and now it seems like my eof (end of file) doesnt work and my program just goes into an endless loop. i was using eof because i need to keep getting data from a file until it reaches the eof.

Answer 1

Answer 2a
Answer 2b

well that makes sense now.......how do i fix it then?

my while loop looked like this
while( ! in_stream.eof())
{
}

i'm a pretty new programmer and a lot of that stuff that you sent me to kind of went over my head.

Use the return code from the function doing the reading to determine when eof is reached.

Post the bit that is doing the reading.

heres the whole code......the eof while statement takes place in the input function

Code:

---

#include <iostream>
#include <fstream>
#include <stddef.h>
#include <stdlib.h>
#include <ctype.h>
#include <string>

using namespace std;

struct StackFrame
{
        string data;
        StackFrame *link;
};

typedef StackFrame* StackFramePtr;


class search
{
public:
    bool check();  //declare the function check
    void output(StackFramePtr top); //declare the function output
    void input(search sight, char *file);
        void input2(search sight, char *file, StackFramePtr top);
        int a;
        int b;
        int total3;
   
private:
    int total;//variable for total number of strings
        int total2;//variable for number of characters in temp array
        int i;//variable for number of strings in array
        int j;//variable for number of characters in a string
        int m;//variable for number of characters in temp string
        int n;//variable for the insert loop
        int s;//variable for ?
    ifstream in_stream; //create an instream
        ofstream out_stream;//creat an outstream
        char array[1000][30];//create an array
        char temp[1000][30];//create an array
        char next;//variable for next character in
   
       
};

int main()
{
        char *name;
    search sight1;
        sight1.a = 0;
        sight1.b = 0;
        sight1.total3 = 0;
        StackFramePtr top;
        top = new StackFrame;
        for(int h = 0; h < 1; h++)
        {
                if(h == 0)
                {
                  name = "text1.txt";
          sight1.input(sight1, name);
              sight1.input2(sight1, name, top);
                }
                if(h == 1)
                {
                        name = "adams.txt";
                        sight1.input(sight1, name);
                        sight1.input2(sight1, name, top);
                }
                if(h == 2)
                {
                        name = "jefferson.txt";
                        sight1.input(sight1, name);
                        sight1.input2(sight1, name, top);
                }
                if(h == 3)
                {
                        name = "madison.txt";
                        sight1.input(sight1, name);
                        sight1.input2(sight1, name, top);
                }
        }
        sight1.output(top);
        cout << " " << sight1.total3;
        return 0;
       

}

void search::input(search sight, char *file)
{
for(s = 0; s < 1000; s++)
{
  for(m = 0; m < 30; m++)
      temp[s][m] = 'c';
 
}
for(i = 0; i < 1000; i++)
{
        for(j = 0; j < 30; j++)
          array[i][j] = 'd';
       
}
s = 0;
m = 0;
total2 = 0;
total = 0;
i = 0;
j = 0;
in_stream.open(file);
in_stream.get(next);
while(! in_stream.eof())//while next is not end of file
{
    //invariant: next is not the end of the file and next is a part of the file
       
                if(ispunct(next))
                {
                        in_stream.get(next);
                }
                if(isspace(next))//if next is space
                {
                        in_stream.get(next);/*//get next character from file
                        array[i][j] = '\0';//put null to end current string
                    j = 0;//bring number of characters back to zero
                        i++;//start a new string
                        total++;//add one to total number of strings*/
                }
                else//if next is not a space
                {
                        while(isalnum(next))
                        //invariant: next is either a letter or a number and next is a part of the file
                        {
                                temp[s][m] = tolower(next);//put next into temp array
                            m++;//go to next place in temp array
                                total2++;//add one to total number of temp characters in temp string
                                in_stream.get(next);//get next character from file
                        }
               
                        temp[s][m] = '\0';
                        m = 0;//bring back to first character in temp string
                        if(check())//if temp string already in array
                        {
                                in_stream.get(next);//get next character from file
                            s++;
                        }
           
                else//if temp string not already in array
                        {
                                for(n = 0; n < total2; n++)//for every character in temp array
                                //invariant: n is less than total2 and has a place in the array
                                {
                                        array[i][j] = temp[s][n];//add temp character to current place in array
                                    j++;//go to next place in current array
                                }
                                array[i][j] = '\0';
                            in_stream.get(next);//get next character from file
                                i++;//start a new string
                                total++;//add one to total number of strings
                                total2 = 0;//reset number of characters in temp string back to zero
                                s++;
                                if(! in_stream.eof())
                                        j = 0;
                        }
                }
       
}
in_stream.close();
}

void search::output(StackFramePtr top)
{
    while(top != NULL)
        {
                string result;
                result = top->data;
                StackFramePtr temp;
                temp = top;
                top = top->link;
                delete temp;
                cout << result;
        }

}

bool search::check()//function defenition
{
        int sum = 0;//represents sum of coorect letters
        int answer = 0;
        int numstring;//represents string of array
        int x;
        int l = 0;
        int f = 0;
    int totalchar;
        if(total == 0)
                return false;
        for(numstring = 0; numstring < total; numstring++)//loops through all strings in array
        //invariant: numstring is less than c and a[numstring][f] is part of an array
        { 
                totalchar = 0;
        for(f = 0; array[numstring][f] != '\0'; f++)
                //invariant: a[numstring[f] does not equal a null character and a[numstring][f] is part of an array
                {
                        if(isalnum(array[numstring][f]))
                                totalchar++;
                }
        l = 0;
                sum = 0;
                x = 0;
                while((array[numstring][l] != '\0') || (temp[s][x] != '\0'))
                // a[numstring][l] and b[t][x] are both not null characters and they are both parts of arrays
                {
                        if(array[numstring][l] == temp[s][x])
                        {
                            sum++;
                                if(temp[s][x] != '\0')
                              x++;
                                if(array[numstring][l] != '\0')
                                  l++;
                        }
                    else
                        {
                                if(temp[s][x] != '\0')
                                  x++;
                                if(array[numstring][l] != '\0')
                              l++;
                        }
                    if((sum == total2) && (x == l) && (totalchar == sum))
                        answer = 1;
                }
               
        }
        if(answer == 1)
                return(true);
    else
            return(false);
       
}

void search::input2(search sight, char *file, StackFramePtr top)
{
        int j;
        j = 0;/*
        array[i][j] = '?';//add a question mark to current place in array to signal end of array
    i = 0;//reset current string to first string
        j = 0;//reset current character to first character
        top = new StackFrame;
        top->data = array[i];
        top->link = NULL;
        i++;
        while(array[i][j] != '?')//while not end of array
        //invariant: array[i][j] is not a question mark and array[i][j] is part of an array
        {
                StackFramePtr temp;
                temp = new StackFrame;
        temp->data = array[i];
                i++;
                temp->link = top;
                top = temp;
        }*/
}

---

Rather than me deciphering your code, tell me what it is supposed to do. What does the input look like, what are you trying to do with it.

That input function looks a mess (sorry!). I would suggest you have only one call to the read function (.get() in this case), and control the loop around that. But once I know what you're trying to do, I can advise you better.

i'm trying to read text from a file and store the words in an array, i then want to to store the words as strings in a linked list so that they point to what files the words appear in. basically a search engine. i'm pretty sure the problem has something to do with me using namespace std and that screwing up the eof while loop i use in the input function