Having trouble with program that reads and prints arrays

[hrstar24]

Im trying to write a program that reads in and prints out arrays. The file that the program reads is a txt file which just looks like

Nixon 200
Ford 300
Kennedy 250
Johnson 453
Dole 319

I have written a program that works well when there arent any words and just prints the numbers, but when i try to do one which reads and prints this out the program compiles but nothing happens. Here is my code:

#include <iostream> 
#include <fstream> 
using namespace std; 
bool trytoread(ifstream *ps,int *pn) 
{ 
  *ps>>*pn; //ps is a pointer... so is pn 
  if (!*ps) 
    return false; 
  return true; 
} 
int main ()  
{ 
  int num; 
     char fname[80];  
  ifstream inStream; cout<<"Enter filename: "; 
  cin>>fname; 
inStream.open(fname);  
  if (!inStream) 
  { 
    cout<<"bad open"; 
    exit(1); 
  } 
  while(trytoread(&inStream,&num)) 
    cout<<num<<endl; 
    system("PAUSE");
    return 0; 

}

[Lindley]

You're trying to read an int when the data in the file is the word "Nixon". What do you expect to happen in this case?

[ThatDinkumThinkum]

By just taking a quick glance at your code, it seems like all you want to do is print what's in the file to the screen. Is that what you want to do?

Also, you are reading in an int, not a string. To print a name you would need to declare a string, then read in the name into the string variable, and then print the variable.

The problem is that you have a function that works only with integers and not strings. Do you need to use the trytoread function? If not then I would not use it.

Instead, try this:

#include <iostream> 
#include <fstream> 

using namespace std;

int main ()
{
     int num=0;
     string name;
     char fname[80];  
     ifstream inStream;

     cout<<"Enter filename: " << endl; 
     cin>>fname;

     inStream.open(fname);

     if (!inStream) 
     { 
         cout<<"bad open"; 
         return 0; 
      }

     while(!inStream.eof())
      {
            inStream >> name;
            inStream >> num;
            cout << name << " " << num << endl;
       }

     return 0;
}

I hope this helps you.

[hrstar24]

oh ok thank you that helped a lot. Now lets say i wanted to read through the text file and print out the one with the maximum amount of votes, how would i do that? I want to be able to do this in two functions as well, so should i create a void function like this?

void maxVotes(num)
{
int x=0;
int i;
for(i=0;i<num;i++)
if votes[i]>votes[x]
x=i;
return x;
}

[Lindley]

That looks just about right, except that normally you'd pass votes into the function as well as num.

[chiragrr]

oh ok thank you that helped a lot. Now lets say i wanted to read through the text file and print out the one with the maximum amount of votes, how would i do that? I want to be able to do this in two functions as well, so should i create a void function like this?

void maxVotes(num)
{
int x=0;
int i;
for(i=0;i<num;i++)
if votes[i]>votes[x]
x=i;
return x;
}

I think you can achieve this in the same function as read.

Initialize two more variables

int maxvotes=0;
string max;
while(!inStream.eof())
      {
            inStream >> name;
            inStream >> num;
            if (num>maxvotes)
            {
                   maxvotes = num;
                   max=name;
             }
            cout << name << " " << num << "Max so far " << max << " with "<<maxvotes<<endl;
       }

[hrstar24]

thanks that helped a lot, but for my program i need to have the max in a seperate function. Im trying to adapt the code, but im having trouble defining the max function and calling the max function in main. How should i go about doing that? The max function should be a void function right?

[Lindley]

Not if you expect to return anything (such as a max index)....

[chiragrr]

Not if you expect to return anything (such as a max index)....

I agree but what about the case where two distinct entries have the same number of votes which is equal to max votes.

If its only about printing values then it can be void function. If you need to do something with the data I would say return an int [] which has all the indices with the max value. You can also pass an integer pointer *num_max to the function to set as to how many values have the max votes