C++ Array problems

[NerdMan]

Hello everyone! I am new to this site and a beginner to C++. My problem today is I want to use an array to look at my file "names.txt" then output how many names it found in the file. It does this, for example, it will output:

yourname [0]
yourname [1]

the above will be shown but will also show blanks leading up to 1000. like this:

yourname [0]
yourname [1]
[2]
[3] .. so on till [999]

all I want outputted is the number of names in the file and it can be just a number value without the actual name first.

any help would be great!

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

int main()
{
	string line;
	string harray[1000];

	ifstream infile("names.txt");

	if (!infile)
	{
		cout << "There was an error opening the file.\n";
		return 0;
	}

	//store words in array
	int i = 0;
	while (infile >> line)
	{
		harray[i] = line;
		i++;
	}

	//output whole array with array position numbers for each entry
	cout << "Array contents:\n";
	for (int i = 0; i<1000; i++)
		cout << harray[i] << "(" << i << ")" << endl;

	system("pause");

	return 0;
}

[E0p9LyTq]

I would suggest using a vector instead of a C-style array. That way you can read a variable number of names. Two added benefits of a vector are:

1. the vector will keep track of the number of items added for you.

2. your vector will resize itself as you add/delete items.

http://www.cplusplus.com/reference/vector/vector/

[NerdMan]

Thanks for the quick response FuryGuy! Also, thanks for the tips but is this even possible using array? If so, I'd love to find out how?

[E0p9LyTq]

The problem with arrays, C-style and the new C++ container class, is they are fixed size. You have to declare how big you want the array to be when creating your array variable, so you need to create an array larger than you estimate you will ever need. Wasted RAM with that.

is this even possible using array

Yes, it is possible, you manually increment a count when you read each item from your file. Then when you display your array contents you simple loop only to the number of items you read in. You could rewrite your code to this:

//store words in array
int count = 0;

while (infile >> line)
{
   harray[i] = line;
   count++;
}

//output whole array with array position numbers for each entry
cout << "Array contents:\n";
for (int i = 0; i < count; i++)
{
   cout << harray[i] << "(" << i << ")" << endl;
}

[Duthomhas]

while ((infile >> line) and (count < num_elements_in_harray))
{
  harray[count++] = line;
}

[NerdMan]

Thank you both for your help! This has completely solved my problem. I was very confused and embarrassed to admit that I spent more than 2 hours on two different days scratching my head on this one...
Thanks again!

[Duthomhas]

I once spent a week trying to figure out what was wrong with my program... I had a } in the wrong spot.