assigning and casting (char) to (int)

[matheo917]

i was just playing around with this and for some reason i can't get to work...

i have a text file (num.txt) which has ONLY 4 characters they are the following: 234'EOF'

what i'm trying to do is to read the 3 characters in untill the (end of file character) thus in result i want to add their values, however all that is being added is their ASCII representations.

I know i can use the insertion operators and input (int) integers, thus i wouldn't have a problem but i want to do it using fin.get() function...

here's the simple code:

#include<fstream>
#include<iostream>
#include<cstdlib>
using namespace std;

int main()
{
	int sum = 0;
	
	char num;

	
	ifstream fin("num.txt");

	if(fin.fail())
	{
		cout << "can't open the file for input\n";
		exit(1);
	}

	else
	{
		fin.get(num);

		while(!fin.eof())
		{
		
			cout << "ASCI : " << (int)num << endl << endl;

			cout << "values : " << num << " " << endl << endl;

			sum = sum + num;

			fin.get(num);
		}

	}

	cout << "The sum of 2 3 4 is: " << sum << endl;

	return 0;

}

Thanks in advance....

ps. i tried using atoi() but i just can't get it to work for some reason... it requires a (char constant) but i can't make this constant....?????

[Sebastiani]

Subtract 48 from the char value to get the equiv integral. You can test the char first by making sure it is >= 48 and <=57. Just look at or print the ASCII chart.

[matheo917]

pretty nifty.....i haven't even thought about that....

thanx

[NewBoy]

I think Im going to go buy
C++ for Dummies or whatever beacuse I herd that it was good for begginers

Is it good?