Thread: counting lines , chars from an input file need help

took out the varible declarations inside of loop. I see why my output was all zeros.... took out the main declarations added ones back into the loops. Still get zero output. this is only an excercise in a book. Man i am not getting it.

always is something small that stumps me for awhile.

>> took out the main declarations added ones back into the loops.
Why? Follow the logic of the program. In the code above, you start your program at the beginning of main. You create a bunch of variables and set their values to zero. Then, inside the loop, you create new variables with the same name. Those new variables are what are used inside the loop. Each time through the loop, you create them again and set them to zero, so nothing is "remembered" each time through. When the loop ends, the code outputs the values of the original variables from the start of main.

If you remove the variable declarations from inside the loop, then when you start the program the original variables are created and set to zero. Each time through the loop they are updated by the loop code. When the loop finishes, they remember their values and so when they are printed out they show non-zero numbers.

Here is the latest. There comes a point where hints do not work. I do not understand why my cout statements are printing what i set them to at the beginning. After the loop is done looping it should print the current values recorded. WHY!

Thanks in advance for your help in advance.

I need someone to state you went wrong RIGHT here to learn this stuff. I have been wrestling with this problem in an endless loop of my own.

Code:

#include <iostream>
#include <fstream>
#include <string>
#include <cassert>
using namespace std;

int main()
{
    char ch;
    unsigned int i=0, line=0, minLine=0, minChars=65535, maxLine=0, maxChars=0, totChars=0;
    
	ifstream inFile("input.txt", ios::in);

    if(!inFile)
        {
            cerr << "File could not be opened!" << "\n";
            exit(1);
		}
		inFile >> ch;

		while(!inFile.eof())
		{
			i++;
			inFile >> ch;
                      
            if ( ch == '\n')
                {
                    line++; /* increment when a newline is found*/
                    totChars += i-1; /* Correction for \n (newline) character*/

                    if (i<minChars)
                        {
                            minChars = i;
							minLine = line;
						}
                        else if (i>maxChars || minChars>maxChars)
                            {
                                maxChars = i;
                                maxLine = line;
							}
							
							i=0;
				}

		}
		cout << "The input file has   " << line << "\n"; 
        cout << "The average number of characters per line is    " << totChars << "\n";
		cout << "The line that is the shortest and its characters is  " << minLine << "   " << minChars << "\n";
		cout << "The line that is the longest and its characters is   " << maxLine << "   " << maxChars << "\n"; 
		return 0;
}

.....

Don't use inFile >> ch. It won't work with your code.

so what will work. please be more specific. two days in idle mode over a program is enough. Point out where my mistakes are

I have already given you the answer. Sure, I've been a little bit cryptic, but it only takes about a minute of work on your part to find it. I've mentioned three times not to use inFile >> ch, and I've explained why even if you didn't understand why. Yet it is still in your code.

I already said I specifically mentioned three different options, and so far we've deduced that two of them won't work with this code. If you can find in my posts the three that I mentioned and tell me what they are, and then perhaps tell me which two we know won't work, then you'll have found the third. If you're not familiar with that function, then you can look up how to use it and ask if you have a specific question about it. At that point I would give you an example that would help in your own code.

You have done well to fix several of the other issues in your code, and when you change the inFile >> part, you will be much closer. You will get non-zero values, but they won't all be exactly right. At least then you'll be able to work on why they aren't quite right.

Thanks for your help almost there

Here is my latest code. I did the get command as you suggested. My book didnt have a good syntax for its usage. I now have the following input file to test the program.

My minimum line and maximum line is off by one digit , for example line 2 says 17 should be 16.

Any suggestions on fixing this. Also the average number of characters per line seems high to me.

Program

Code:

#include <iostream>
#include <fstream>
#include <string>
#include <cassert>
using namespace std;

int main()
{
	

    
    unsigned int i=0, line=0, minLine=0, minChars=65535, maxLine=0, maxChars=0, totChars=0;
	
	ifstream inStream;
	inStream.open("input.txt", ios::in);

	assert( inStream.is_open() );
	
	


    if(!inStream)
        {
            cerr << "File could not be opened!" << "\n";
            exit(1);
		}
		

		while(!inStream.eof())
		{
			i++;
			char ch;
			ch = inStream.get();
						
                      
            if ( ch == '\n')
                {
                    line++; /* increment when a newline is found*/
                    totChars += i-1; /* Correction for \n (newline) character*/

                    if (i<minChars)
                        {
                            minChars = i;
							minLine = line;
						}
                        else if (i>maxChars || minChars>maxChars)
                            {
                                maxChars = i;
                                maxLine = line;
							}
							
							i=0;
				}

		}
		cout << "The input file has   " << line << "\n"; 
        cout << "The average number of characters per line is    " << totChars << "\n";
		cout << "The line that is the shortest and its characters is  " << minLine << "   " << minChars << "\n";
		cout << "The line that is the longest and its characters is   " << maxLine << "   " << maxChars << "\n"; 
		return 0;
}

Input.txt

Code:

aaaaaaaaaaaaaaaa
0100111101010010
01000111
0100010001000101
01000011
0100100001000101
01011000
0100010101001110
01000100

My output is:

input file has 9 lines

average number of characters per line is 112

The line that is the shortest and its characters 3 9

The line that is the longest and its characters 2 17

I figured it out , -1 on min and max and added a new varible called average -- totchars / line to get my average per line.

Thanks david for putting up with me.

Good job. I'm glad you got it working.