Putting data into an array

[zbREy60M]

Hello,

I'm trying to write a program that generates a series of random coordinates. Right now, I've only gotten to the part where I am generating one random number. I can cout this so that I can see the number, but when I use myfile to output it into a .txt file I only get the first data point. This makes me think that I need to put the data into an array and then output that. The problem is that I can't figure out how to put these numbers into an array. In the "while" loop I keep getting errors like "cannot allocate an array of constant size 0" and "cannot convert from double to double[]", can anyone help me with this? Thanks!

*As an added note if I change the array called radius into just a double, and then have it cout radius 'm' times, then it works just fine and I get 'm' random numbers. However if I declare radius to be an array of size 'i' then i get an error. If I declare it to be of size 'm' then I just get the same random number 'm' times.

int main()
{
int i = 0;
double normalization = rand() % 32000;
seed();
int m ;
cout << "How many gravitars?\n\n";
cin >> m;

while (i < m)
{

double radius[i] = unifRand()*(normalization);
i++;
cout << radius[i] << endl;
}
system("PAUSE");
return 0;
}

[Disch]

double radius[i] = unifRand()*(normalization);

You can't declare an array like this.

Really, radius doesn't need to be an array, just make it a normal var:

double radius = unifRand()*(normalization);  // get rid of the [i]
i++;
cout << radius << endl;  // here too 

EDIT:

or, if you need it to be an array, you'll have to declare the array outside the loop and give it the total size (in this case, that's 'm'):

double* radius = new double[m];
for(i = 0; i < m; ++i)
{
  radius[i] = blah;
  cout << radius[i] << endl;
}

delete[] radius;  // don't forget to delete[] stuff that you new[]'d 

Also note you shouldn't increment i before printing radius[i] or you will be printing the wrong radius. I changed it to a for loop here to correct that problem and also because it's more "normal" and intuitive for this kind of loop.

[zbREy60M]

This is similar to how I had it before, in which it worked fine and if I entered '50' then it would cout 50 random numbers, which is exactly what I need. However, when I went to export them to text file, I would only get the first number. How would I go about exporting ALL the data to a txt file? I was just assuming I would need an array to do that.