Error Checking in Program Help

[billbarr]

Hey guys,

Have a program that I've been working on that is supposed to check whether a user inputs valid numbers. In the segment of code that I'm working on, you'll see the numbers, so that's self explanatory.

I think I have a pretty good idea of what I'm doing wrong, but I think it's good to post the whole thing to show my logic and the best way for me to fix it.

Segment of not-working code:

 double value;
    if (! (value <= 100.0 && value >= 0.0))
      {
	cout << "Invalid value. Must be between 1 and 100." << endl;
	cout << "Program will now terminate. Try again later." << endl;
	return 1;
      }
    else
      {
	readVector (v1);
	readVector (v2);
	setOutputDigits (1);

	printVectors (v1, "Vector 1 => ");
	cout << endl;
	printVectors (v2, "Vector 2 => ");
	cout << endl;
      }

Here's my readVector function:

void
readVector(vector<double> & v)
{
  unsigned int i = 0;
  while ((i < v.size ()) && (cin >> v[i])) {
    i++;
  }
}

The code is designed to check whether the user inputs a valid floating point number, yet it doesn't actually check. I think it's because value has nothing to do with readVector so the check isn't occurring.

How would I format this code so that it would check the input and terminate when a number such as 101 or -5 is inputted?

Thanks!

[petersrolo]

You must give your variable value an actual value before you check it in your if statement. Here you haven't.

double value;
cin >> value;
if(//check 0<value<100) 

[billbarr]

Right, I forgot to mention that I did use cin to see if that accomplished anything.

The problem with cin >> value in this case is that I'm using my readVector function to determine values.

My thinking is that I would set value to 0, check readVector(v1) and readVector(v2), and increment value. Not sure though.

[billbarr]

Can anybody lead me in the right direction please?

[billbarr]

Still looking for help with this.